Patent Publication Number: US-11650786-B2

Title: Device grouping

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This disclosure claims the benefit of priority as a continuation under 35 U.S.C. § 120 to U.S. application Ser. No. 16/277,788 entitled “Device Grouping” filed on Feb. 15, 2019, which claims the benefit of priority as a continuation under 35 U.S.C. § 120 to U.S. application Ser. No. 14/338,710 entitled “Device Grouping” filed on Jul. 23, 2014, the contents of which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The disclosure is related to consumer goods and, more particularly, to methods, systems, products, features, services, and other elements directed to media playback or some aspect thereof. 
     BACKGROUND 
     Options for accessing and listening to digital audio in an out-loud setting were limited until in 2003, when SONOS, Inc. filed for one of its first patent applications, entitled “Method for Synchronizing Audio Playback between Multiple Networked Devices,” and began offering a media playback system for sale in 2005. The Sonos Wireless HiFi System enables people to experience music from many sources via one or more networked playback devices. Through a software control application installed on a smartphone, tablet, or computer, one can play what he or she wants in any room that has a networked playback device. Additionally, using the controller, for example, different songs can be streamed to each room with a playback device, rooms can be grouped together for synchronous playback, or the same song can be heard in all rooms synchronously. 
     Given the ever growing interest in digital media, there continues to be a need to develop consumer-accessible technologies to further enhance the listening experience. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, aspects, and advantages of the presently disclosed technology may be better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG.  1    shows an example media playback system configuration in which certain embodiments may be practiced; 
         FIG.  2    shows a functional block diagram of an example playback device; 
         FIG.  3    shows a functional block diagram of an example control device; 
         FIG.  4    shows an example controller interface; 
         FIG.  5 A  shows an example flow diagram for an example method; 
         FIG.  5 B  shows an example control interface; 
         FIG.  5 C  shows another example control interface; 
         FIG.  5 D  shows yet another example control interface; 
         FIG.  6    shows example events and example devices; 
         FIG.  7    shows an example flow diagram for another example method; and 
         FIG.  8    shows an example bonded controller. 
     
    
    
     The drawings are for the purpose of illustrating example embodiments, but it is understood that the inventions are not limited to the arrangements and instrumentality shown in the drawings. 
     DETAILED DESCRIPTION 
     I. Overview 
     In some situations, control of a media playback system that includes multiple playback devices may occur by way of a control device communicatively coupled to one or more of the playback devices. The control device could be, for example, a smart phone or a tablet computer that is arranged to control the playback devices. The control device may provide an interface for control or customization of playback of media by the playback devices in a variety of ways. For example, the control device may respectively associate several playback devices located in a user&#39;s home between first and second zones (or more zones) so that playback devices in the first zone (e.g., a living room) play back a first media in synchrony and playback devices in the second zone (e.g., a patio) play back a second media in synchrony. As another example, the control device may control playback volumes corresponding to playback devices of the first and second zones. 
     However, control of the first playback device by way of a separate control device may in some respects or situations be inefficient or otherwise undesirable. As such, according to some examples described here, the first playback device may be controlled by way of input detected at a control interface of the first playback device. For example, one control action may involve having a first playback device (perhaps not currently playing back media) join an existing zone that includes a second playback device currently playing back media. For instance, the control interface of the first playback device may include one or more push-buttons. A push of such a push-button (or other such suitable input) at the control interface may cause the first playback device to form a “zone” with the second playback device that is currently playing back media. Such an input may also cause the first playback device to playback the media in synchrony with at least the second playback device. 
     In other examples, the input detected at the control interface of the first playback device could also be used to control at least a third playback device. For instance, before the input is detected at the control interface, the first and third playback devices may be within a first zone (e.g., a “bonded pair” in some instances), and in response to detecting the input, the first playback device may cause both the first and third playback devices to leave the first zone to join a second zone that includes the second playback device. After joining the second zone, the first and third playback devices may playback media in synchrony with the second playback device. In another example, in response to the input, the third playback device may remain in the first zone and play back media that corresponds to the first zone, while the first playback device nonetheless joins the second zone and plays back media with the second playback device. 
     Additionally, instead of control by way of a control interface attached to the first playback device, control may occur by way of a controller that is communicatively coupled with the first playback device but that is not communicatively coupled with the second playback device. In some examples, such a controller may provide a physical interface for input, but not a graphical interface. In some circumstances, using the bonded controller for control of the first playback device rather than a control device communicatively coupled or otherwise arranged to control multiple playback devices may be more efficient. As such, input to the bonded controller may indicate a command for the first playback device to form a zone with the second playback device and to playback the media in synchrony with the second playback device. 
     Accordingly, some examples described herein involve, among other things, detecting an input at a control interface or a bonded controller of a first playback device so that the first playback device (i) forms a zone with a second playback device that is already playing back media and (ii) plays back the media in synchrony with the at least one second playback device. Other aspects of the examples will be made apparent in the remainder of the description herein. 
     In one aspect, a method is provided. The method involves detecting, via a control interface of a first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) play back the media in synchrony with the at least one second playback device and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to play back the media in synchrony with the at least one second playback device. 
     In another aspect, a first playback device is provided. The first playback device includes a processor and memory storing instructions that when executed by the first playback device, cause the first playback device to perform functions. The functions include detecting, via a control interface of the first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) play back the media in synchrony with the at least one second playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to play back the media in synchrony with the at least one second playback device. 
     In yet another aspect, a non-transitory computer readable memory is provided. The non-transitory computer readable memory has stored thereon instructions executable by a first playback device to cause the first playback device to perform functions. The functions include detecting, via a control interface of the first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) play back the media in synchrony with the at least one second playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to play back the media in synchrony with the at least one second playback device. 
     In another aspect, a method is provided. The method involves detecting, by a control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) play back the media in synchrony with the at least one first playback device, wherein the control device is communicatively coupled to the second playback device and not communicatively coupled to the first playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to play back the media in synchrony with the at least one first playback device. 
     In another aspect, a control device is provided. The control device includes a processor and memory storing instructions that when executed by the control device, cause the control device to perform functions. The functions include detecting, by the control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) play back the media in synchrony with the at least one first playback device, wherein the control device is communicatively coupled to the second playback device and not communicatively coupled to the first playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to play back the media in synchrony with the at least one first playback device. 
     In yet another aspect, a non-transitory computer readable memory is provided. The non-transitory computer readable memory has stored thereon instructions executable by a control device to perform functions. The functions include detecting, by the control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) play back the media in synchrony with the at least one first playback device, wherein the control device is communicatively coupled to the second playback device and not communicatively coupled to the first playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to play back the media in synchrony with the at least one first playback device. 
     It will be understood by one of ordinary skill in the art that this disclosure includes numerous other embodiments. While some examples described herein may refer to functions performed by given actors such as “users” and/or other entities, it should be understood that this is for purposes of explanation only. The claims should not be interpreted to require action by any such example actor unless explicitly required by the language of the claims themselves. 
     II. Example Operating Environment 
       FIG.  1    shows an example configuration of a media playback system  100  in which one or more embodiments disclosed herein may be practiced or implemented. The media playback system  100  as shown is associated with an example home environment having several rooms and spaces, such as for example, a master bedroom, an office, a dining room, and a living room. As shown in the example of  FIG.  1   , the media playback system  100  includes playback devices  102 - 124 , control devices  126  and  128 , and a wired or wireless network router  130 . 
     Further discussions relating to the different components of the example media playback system  100  and how the different components may interact to provide a user with a media experience may be found in the following sections. While discussions herein may generally refer to the example media playback system  100 , technologies described herein are not limited to applications within, among other things, the home environment as shown in  FIG.  1   . For instance, the technologies described herein may be useful in environments where multi-zone audio may be desired, such as, for example, a commercial setting like a restaurant, mall or airport, a vehicle like a sports utility vehicle (SUV), bus or car, a ship or boat, an airplane, and so on. 
     a. Example Playback Devices 
       FIG.  2    shows a functional block diagram of an example playback device  200  that may be configured to be one or more of the playback devices  102 - 124  of the media playback system  100  of  FIG.  1   . The playback device  200  may include a processor  202 , software components  204 , memory  206 , audio processing components  208 , audio amplifier(s)  210 , speaker(s)  212 , and a network interface  214  including wireless interface(s)  216  and wired interface(s)  218 . In one case, the playback device  200  may not include the speaker(s)  212 , but rather a speaker interface for connecting the playback device  200  to external speakers. In another case, the playback device  200  may include neither the speaker(s)  212  nor the audio amplifier(s)  210 , but rather an audio interface for connecting the playback device  200  to an external audio amplifier or audio-visual receiver. 
     In one example, the processor  202  may be a clock-driven computing component configured to process input data according to instructions stored in the memory  206 . The memory  206  may be a tangible computer-readable medium configured to store instructions executable by the processor  202 . For instance, the memory  206  may be data storage that can be loaded with one or more of the software components  204  executable by the processor  202  to achieve certain functions. In one example, the functions may involve the playback device  200  retrieving audio data from an audio source or another playback device. In another example, the functions may involve the playback device  200  sending audio data to another device or playback device on a network. In yet another example, the functions may involve pairing of the playback device  200  with one or more playback devices to create a multi-channel audio environment. 
     Certain functions may involve the playback device  200  synchronizing playback of audio content with one or more other playback devices. During synchronous playback, a listener will preferably not be able to perceive time-delay differences between playback of the audio content by the playback device  200  and the one or more other playback devices. U.S. Pat. No. 8,234,395 entitled, “System and method for synchronizing operations among a plurality of independently clocked digital data processing devices,” which is hereby incorporated by reference, provides in more detail some examples for audio playback synchronization among playback devices. 
     The memory  206  may further be configured to store data associated with the playback device  200 , such as one or more zones and/or zone groups the playback device  200  is a part of, audio sources accessible by the playback device  200 , or a playback queue that the playback device  200  (or some other playback device) may be associated with. The data may be stored as one or more state variables that are periodically updated and used to describe the state of the playback device  200 . The memory  206  may also include the data associated with the state of the other devices of the media system, and shared from time to time among the devices so that one or more of the devices have the most recent data associated with the system. Other embodiments are also possible. 
     The audio processing components  208  may include one or more digital-to-analog converters (DAC), an audio preprocessing component, an audio enhancement component or a digital signal processor (DSP), and so on. In one embodiment, one or more of the audio processing components  208  may be a subcomponent of the processor  202 . In one example, audio content may be processed and/or intentionally altered by the audio processing components  208  to produce audio signals. The produced audio signals may then be provided to the audio amplifier(s)  210  for amplification and playback through speaker(s)  212 . Particularly, the audio amplifier(s)  210  may include devices configured to amplify audio signals to a level for driving one or more of the speakers  212 . The speaker(s)  212  may include an individual transducer (e.g., a “driver”) or a complete speaker system involving an enclosure with one or more drivers. A particular driver of the speaker(s)  212  may include, for example, a subwoofer (e.g., for low frequencies), a mid-range driver (e.g., for middle frequencies), and/or a tweeter (e.g., for high frequencies). In some cases, each transducer in the one or more speakers  212  may be driven by an individual corresponding audio amplifier of the audio amplifier(s)  210 . In addition to producing analog signals for playback by the playback device  200 , the audio processing components  208  may be configured to process audio content to be sent to one or more other playback devices for playback. 
     Audio content to be processed and/or played back by the playback device  200  may be received from an external source, such as via an audio line-in input connection (e.g., an auto-detecting 3.5 mm audio line-in connection) or the network interface  214 . 
     The network interface  214  may be configured to facilitate a data flow between the playback device  200  and one or more other devices on a data network. As such, the playback device  200  may be configured to receive audio content over the data network from one or more other playback devices in communication with the playback device  200 , network devices within a local area network, or audio content sources over a wide area network such as the Internet. In one example, the audio content and other signals transmitted and received by the playback device  200  may be transmitted in the form of digital packet data containing an Internet Protocol (IP)-based source address and IP-based destination addresses. In such a case, the network interface  214  may be configured to parse the digital packet data such that the data destined for the playback device  200  is properly received and processed by the playback device  200 . 
     As shown, the network interface  214  may include wireless interface(s)  216  and wired interface(s)  218 . The wireless interface(s)  216  may provide network interface functions for the playback device  200  to wirelessly communicate with other devices (e.g., other playback device(s), speaker(s), receiver(s), network device(s), control device(s) within a data network the playback device  200  is associated with) in accordance with a communication protocol (e.g., any wireless standard including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G mobile communication standard, and so on). The wired interface(s)  218  may provide network interface functions for the playback device  200  to communicate over a wired connection with other devices in accordance with a communication protocol (e.g., IEEE 802.3). While the network interface  214  shown in  FIG.  2    includes both wireless interface(s)  216  and wired interface(s)  218 , the network interface  214  may in some embodiments include only wireless interface(s) or only wired interface(s). 
     In one example, the playback device  200  and one other playback device may be paired to play two separate audio components of audio content. For instance, playback device  200  may be configured to play a left channel audio component, while the other playback device may be configured to play a right channel audio component, thereby producing or enhancing a stereo effect of the audio content. The paired playback devices (also referred to as “bonded playback devices”) may further play audio content in synchrony with other playback devices. 
     In another example, the playback device  200  may be sonically consolidated with one or more other playback devices to form a single, consolidated playback device. A consolidated playback device may be configured to process and reproduce sound differently than an unconsolidated playback device or playback devices that are paired, because a consolidated playback device may have additional speaker drivers through which audio content may be rendered. For instance, if the playback device  200  is a playback device designed to render low frequency range audio content (i.e. a subwoofer), the playback device  200  may be consolidated with a playback device designed to render full frequency range audio content. In such a case, the full frequency range playback device, when consolidated with the low frequency playback device  200 , may be configured to render only the mid and high frequency components of audio content, while the low frequency range playback device  200  renders the low frequency component of the audio content. The consolidated playback device may further be paired with a single playback device or yet another consolidated playback device. 
     By way of illustration, SONOS, Inc. presently offers (or has offered) for sale certain playback devices including a “PLAY:1,” “PLAY:3,” “PLAY:5,” “PLAYBAR,” “CONNECT:AMP,” “CONNECT,” and “SUB.” Any other past, present, and/or future playback devices may additionally or alternatively be used to implement the playback devices of example embodiments disclosed herein. Additionally, it is understood that a playback device is not limited to the example illustrated in  FIG.  2    or to the SONOS product offerings. For example, a playback device may include a wired or wireless headphone. In another example, a playback device may include or interact with a docking station for personal mobile media playback devices. In yet another example, a playback device may be integral to another device or component such as a television, a lighting fixture, or some other device for indoor or outdoor use. 
     b. Example Playback Zone Configurations 
     Referring back to the media playback system  100  of  FIG.  1   , the environment may have one or more playback zones, each with one or more playback devices. The media playback system  100  may be established with one or more playback zones, after which one or more zones may be added, or removed to arrive at the example configuration shown in  FIG.  1   . Each zone may be given a name according to a different room or space such as an office, bathroom, master bedroom, bedroom, kitchen, dining room, living room, and/or balcony. In one case, a single playback zone may include multiple rooms or spaces. In another case, a single room or space may include multiple playback zones. 
     As shown in  FIG.  1   , the balcony, dining room, kitchen, bathroom, office, and bedroom zones each have one playback device, while the living room and master bedroom zones each have multiple playback devices. In the living room zone, playback devices  104 ,  106 ,  108 , and  110  may be configured to play audio content in synchrony as individual playback devices, as one or more bonded playback devices, as one or more consolidated playback devices, or any combination thereof. Similarly, in the case of the master bedroom, playback devices  122  and  124  may be configured to play audio content in synchrony as individual playback devices, as a bonded playback device, or as a consolidated playback device. 
     In one example, one or more playback zones in the environment of  FIG.  1    may each be playing different audio content. For instance, the user may be grilling in the balcony zone and listening to hip hop music being played by the playback device  102  while another user may be preparing food in the kitchen zone and listening to classical music being played by the playback device  114 . In another example, a playback zone may play the same audio content in synchrony with another playback zone. For instance, the user may be in the office zone where the playback device  118  is playing the same rock music that is being playing by playback device  102  in the balcony zone. In such a case, playback devices  102  and  118  may be playing the rock music in synchrony such that the user may seamlessly (or at least substantially seamlessly) enjoy the audio content that is being played out-loud while moving between different playback zones. Synchronization among playback zones may be achieved in a manner similar to that of synchronization among playback devices, as described in previously referenced U.S. Pat. No. 8,234,395. 
     As suggested above, the zone configurations of the media playback system  100  may be dynamically modified, and in some embodiments, the media playback system  100  supports numerous configurations. For instance, if a user physically moves one or more playback devices to or from a zone, the media playback system  100  may be reconfigured to accommodate the change(s). For instance, if the user physically moves the playback device  102  from the balcony zone to the office zone, the office zone may now include both the playback device  118  and the playback device  102 . The playback device  102  may be paired or grouped with the office zone and/or renamed if so desired via a control device such as the control devices  126  and  128 . On the other hand, if the one or more playback devices are moved to a particular area in the home environment that is not already a playback zone, a new playback zone may be created for the particular area. 
     Further, different playback zones of the media playback system  100  may be dynamically combined into zone groups or split up into individual playback zones. For instance, the dining room zone and the kitchen zone  114  may be combined into a zone group for a dinner party such that playback devices  112  and  114  may render audio content in synchrony. On the other hand, the living room zone may be split into a television zone including playback device  104 , and a listening zone including playback devices  106 ,  108 , and  110 , if the user wishes to listen to music in the living room space while another user wishes to watch television. 
     c. Example Control Devices 
       FIG.  3    shows a functional block diagram of an example control device  300  that may be configured to be one or both of the control devices  126  and  128  of the media playback system  100 . As shown, the control device  300  may include a processor  302 , memory  304 , a network interface  306 , and a user interface  308 . In one example, the control device  300  may be a dedicated controller for the media playback system  100 . In another example, the control device  300  may be a network device on which media playback system controller application software may be installed, such as for example, an iPhone™, iPad™ or any other smart phone, tablet or network device (e.g., a networked computer such as a PC or Mac™). 
     The processor  302  may be configured to perform functions relevant to facilitating user access, control, and configuration of the media playback system  100 . The memory  304  may be configured to store instructions executable by the processor  302  to perform those functions. The memory  304  may also be configured to store the media playback system controller application software and other data associated with the media playback system  100  and the user. 
     In one example, the network interface  306  may be based on an industry standard (e.g., infrared, radio, wired standards including IEEE 802.3, wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G mobile communication standard, and so on). The network interface  306  may provide a means for the control device  300  to communicate with other devices in the media playback system  100 . In one example, data and information (e.g., such as a state variable) may be communicated between control device  300  and other devices via the network interface  306 . For instance, playback zone and zone group configurations in the media playback system  100  may be received by the control device  300  from a playback device or another network device, or transmitted by the control device  300  to another playback device or network device via the network interface  306 . In some cases, the other network device may be another control device. 
     Playback device control commands such as volume control and audio playback control may also be communicated from the control device  300  to a playback device via the network interface  306 . As suggested above, changes to configurations of the media playback system  100  may also be performed by a user using the control device  300 . The configuration changes may include adding/removing one or more playback devices to/from a zone, adding/removing one or more zones to/from a zone group, forming a bonded or consolidated player, separating one or more playback devices from a bonded or consolidated player, among others. Accordingly, the control device  300  may sometimes be referred to as a controller, whether the control device  300  is a dedicated controller or a network device on which media playback system controller application software is installed. 
     The user interface  308  of the control device  300  may be configured to facilitate user access and control of the media playback system  100 , by providing a controller interface such as the controller interface  400  shown in  FIG.  4   . The controller interface  400  includes a playback control region  410 , a playback zone region  420 , a playback status region  430 , a playback queue region  440 , and an audio content sources region  450 . The user interface  400  as shown is just one example of a user interface that may be provided on a network device such as the control device  300  of  FIG.  3    (and/or the control devices  126  and  128  of  FIG.  1   ) and accessed by users to control a media playback system such as the media playback system  100 . Other user interfaces of varying formats, styles, and interactive sequences may alternatively be implemented on one or more network devices to provide comparable control access to a media playback system. 
     The playback control region  410  may include selectable (e.g., by way of touch or by using a cursor) icons to cause playback devices in a selected playback zone or zone group to play or pause, fast forward, rewind, skip to next, skip to previous, enter/exit shuffle mode, enter/exit repeat mode, enter/exit cross fade mode. The playback control region  410  may also include selectable icons to modify equalization settings, and playback volume, among other possibilities. 
     The playback zone region  420  may include representations of playback zones within the media playback system  100 . In some embodiments, the graphical representations of playback zones may be selectable to bring up additional selectable icons to manage or configure the playback zones in the media playback system, such as a creation of bonded zones, creation of zone groups, separation of zone groups, and renaming of zone groups, among other possibilities. 
     For example, as shown, a “group” icon may be provided within each of the graphical representations of playback zones. The “group” icon provided within a graphical representation of a particular zone may be selectable to bring up options to select one or more other zones in the media playback system to be grouped with the particular zone. Once grouped, playback devices in the zones that have been grouped with the particular zone will be configured to play audio content in synchrony with the playback device(s) in the particular zone. Analogously, a “group” icon may be provided within a graphical representation of a zone group. In this case, the “group” icon may be selectable to bring up options to deselect one or more zones in the zone group to be removed from the zone group. Other interactions and implementations for grouping and ungrouping zones via a user interface such as the user interface  400  are also possible. The representations of playback zones in the playback zone region  420  may be dynamically updated as playback zone or zone group configurations are modified. 
     The playback status region  430  may include graphical representations of audio content that is presently being played, previously played, or scheduled to play next in the selected playback zone or zone group. The selected playback zone or zone group may be visually distinguished on the user interface, such as within the playback zone region  420  and/or the playback status region  430 . The graphical representations may include track title, artist name, album name, album year, track length, and other relevant information that may be useful for the user to know when controlling the media playback system via the user interface  400 . 
     The playback queue region  440  may include graphical representations of audio content in a playback queue associated with the selected playback zone or zone group. In some embodiments, each playback zone or zone group may be associated with a playback queue containing information corresponding to zero or more audio items for playback by the playback zone or zone group. For instance, each audio item in the playback queue may comprise a uniform resource identifier (URI), a uniform resource locator (URL) or some other identifier that may be used by a playback device in the playback zone or zone group to find and/or retrieve the audio item from a local audio content source or a networked audio content source, possibly for playback by the playback device. 
     In one example, a playlist may be added to a playback queue, in which case information corresponding to each audio item in the playlist may be added to the playback queue. In another example, audio items in a playback queue may be saved as a playlist. In a further example, a playback queue may be empty, or populated but “not in use” when the playback zone or zone group is playing continuously streaming audio content, such as Internet radio that may continue to play until otherwise stopped, rather than discrete audio items that have playback durations. In an alternative embodiment, a playback queue can include Internet radio and/or other streaming audio content items and be “in use” when the playback zone or zone group is playing those items. Other examples are also possible. 
     When playback zones or zone groups are “grouped” or “ungrouped,” playback queues associated with the affected playback zones or zone groups may be cleared or re-associated. For example, if a first playback zone including a first playback queue is grouped with a second playback zone including a second playback queue, the established zone group may have an associated playback queue that is initially empty, that contains audio items from the first playback queue (such as if the second playback zone was added to the first playback zone), that contains audio items from the second playback queue (such as if the first playback zone was added to the second playback zone), or a combination of audio items from both the first and second playback queues. Subsequently, if the established zone group is ungrouped, the resulting first playback zone may be re-associated with the previous first playback queue, or be associated with a new playback queue that is empty or contains audio items from the playback queue associated with the established zone group before the established zone group was ungrouped. Similarly, the resulting second playback zone may be re-associated with the previous second playback queue, or be associated with a new playback queue that is empty, or contains audio items from the playback queue associated with the established zone group before the established zone group was ungrouped. Other examples are also possible. 
     Referring back to the user interface  400  of  FIG.  4   , the graphical representations of audio content in the playback queue region  440  may include track titles, artist names, track lengths, and other relevant information associated with the audio content in the playback queue. In one example, graphical representations of audio content may be selectable to bring up additional selectable icons to manage and/or manipulate the playback queue and/or audio content represented in the playback queue. For instance, a represented audio content may be removed from the playback queue, moved to a different position within the playback queue, or selected to be played immediately, or after any currently playing audio content, among other possibilities. A playback queue associated with a playback zone or zone group may be stored in a memory on one or more playback devices in the playback zone or zone group, on a playback device that is not in the playback zone or zone group, and/or some other designated device. 
     The audio content sources region  450  may include graphical representations of selectable audio content sources from which audio content may be retrieved and played by the selected playback zone or zone group. Discussions pertaining to audio content sources may be found in the following section. 
     d. Example Audio Content Sources 
     As indicated previously, one or more playback devices in a zone or zone group may be configured to retrieve for playback audio content (e.g. according to a corresponding URI or URL for the audio content) from a variety of available audio content sources. In one example, audio content may be retrieved by a playback device directly from a corresponding audio content source (e.g., a line-in connection). In another example, audio content may be provided to a playback device over a network via one or more other playback devices or network devices. 
     Example audio content sources may include a memory of one or more playback devices in a media playback system such as the media playback system  100  of  FIG.  1   , local music libraries on one or more network devices (such as a control device, a network-enabled personal computer, or a networked-attached storage (NAS), for example), streaming audio services providing audio content via the Internet (e.g., the cloud), or audio sources connected to the media playback system via a line-in input connection on a playback device or network devise, among other possibilities. 
     In some embodiments, audio content sources may be regularly added or removed from a media playback system such as the media playback system  100  of  FIG.  1   . In one example, an indexing of audio items may be performed whenever one or more audio content sources are added, removed or updated. Indexing of audio items may involve scanning for identifiable audio items in all folders/directory shared over a network accessible by playback devices in the media playback system, and generating or updating an audio content database containing metadata (e.g., title, artist, album, track length, among others) and other associated information, such as a URI or URL for each identifiable audio item found. Other examples for managing and maintaining audio content sources may also be possible. 
     The above discussions relating to playback devices, controller devices, playback zone configurations, and media content sources provide only some examples of operating environments within which functions and methods described below may be implemented. Other operating environments and configurations of media playback systems, playback devices, and network devices not explicitly described herein may also be applicable and suitable for implementation of the functions and methods. 
     III. Example Method for Controlling a Media Playback System 
     As discussed above, some examples described herein involve, among other things, detecting input at a control interface of a first playback device or a bonded controller of the first playback device such that the first playback device (i) forms a zone with a second playback device that is currently playing back media and (ii) plays back the media in synchrony with the at least one second playback device. Other aspects of the examples will be made apparent in the remainder of the description herein. 
     In this section the term “computing device” may have the same meaning as the terms “network device” and/or “controller device” used in previous sections, unless it is clear from context that this is not the case. The term “server” may also be used interchangeably with the term “server device.” Terminology such as “server,” “server device,” “controller,” “controller device,” “network device,” and “computing device” are generally used for explanatory purposes in this disclosure and are not meant to be limiting. One of skill in the art will recognize that any suitable computing device may perform various functions disclosed herein and that the preceding list of terms is non-exhaustive. 
     Method  500  shown in  FIG.  5 A  presents an example method that can be implemented within an operating environment involving, for example, the media playback system  100  of  FIG.  1    and one or more of the playback device  200  of  FIG.  2   . Method  500  may include one or more operations, functions, or actions as illustrated by one or more of blocks  502  and  504 . Although the blocks are illustrated in sequential order, these blocks may also be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon the desired implementation. 
     In addition, for the method  500  and other processes and methods disclosed herein, the flowchart shows functionality and operation of one possible implementation of present embodiments. In this regard, each block may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor for implementing specific logical functions or steps in the process. The program code may be stored on any type of computer readable medium, for example, such as a storage device including a disk or hard drive. The computer readable medium may include non-transitory computer readable medium, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device. In addition, for the method  500  and other processes and methods disclosed herein, each block in  FIG.  5    may represent circuitry that is wired to perform the specific logical functions in the process. 
     At block  502 , the method includes detecting, via a control interface of a first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) playback the media in synchrony with the at least one second playback device. Detecting the input may involve receiving the input at the control interface of the first playback device. 
     For instance, the control interface of the first playback device may include a push-button, a knob, a switch, a keypad, a touchscreen graphical interface, or other controls for receiving input. As an example,  FIG.  5 B  shows a control interface that includes a first push-button  512 , a second push-button  514 , and a third push-button  516 . Such an example control interface may include additional and/or alternative controls as well. 
     The first push-button  512  may receive input, and in response cause the first playback device (or other playback devices included in a zone with the first playback device) to (i) start, resume, or pause playback of media, or (ii) form a zone with another playback device (e.g., the second playback device). For instance a push and release input to the first push-button  512  may cause the first playback device to start, resume, or pause playback of media, whereas a push and hold input to the first push-button  512  may cause the first playback device to form a zone with another playback device. The first push-button  512  receiving input may cause the first playback device to perform other functions as well. 
     By further example, the second push-button  514  may receive input and cause the first playback device (or other playback devices included in a zone with the first playback device) to increase playback volume. The third push-button  516  may also receive input and cause the first playback device to decrease playback volume. Inputs received at the second push-button  514  and the third push-button  516  may cause the first playback device to perform other functions as well. 
     In another example, the control interface may include a touchscreen or similar interactive display, such as depicted in  FIG.  5 C . In some cases, the touchscreen  520  may provide a visual indication  522  of media (e.g., text or icons) that is playing back by the first playback device. Also, the touchscreen  520  may include an area  524  designated to receive or detect inputs related to controlling playback of media by the first playback device (or also other playback devices). In one example, the area  526  may be designated to detect an input, and in response, cause the first playback device to form a zone with at least the second playback device. However, in other examples, the area  526  may detect inputs representing commands for the first playback device to perform other functions as well. 
     In yet another example depicted by  FIG.  5 D , a control interface  540  may include several push-buttons. For example, receiving input at push-button  530  may cause the first playback device to form the zone with at least the second playback device. Receiving input at push-button  532  may cause the first playback device (or also other playback devices) to advance through a playback queue in a first direction, receiving input at push-button  534  may cause the first playback device (or also other playback devices) to begin playback of media, receiving input at push-button  536  may cause the first playback device (or also other playback devices) to pause playback of media, and receiving input at push-button  538  may cause the first playback device (or also other playback devices) to advance through a playback queue in a second direction. 
     Referring back to  FIG.  5 A , forming the zone at block  504  could include (i) forming a zone whereby playback devices of the zone are configured to play back media in synchrony with other playback devices of the zone, (ii) forming a group of zones whereby playback devices of the group of zones are configured to play back media in synchrony with other playback devices of the group of zones, or (iii) forming a zone whereby playback functions (e.g., pause, play, track repeat, track shuffle, or volume) of playback devices of the zone are configured to be controlled in unison via input(s) received at the first playback device and/or another controller. 
     As an illustrative example, a control interface of playback device  112  of  FIG.  1    may receive the input. As depicted at block  504 , in response to detecting the input, the playback device  112  may form a zone (e.g., join a zone) that includes playback devices  114  and  118 . Playback devices  114  and  118  may be playing back media when the input is detected at playback device  112 . Then, playback device  112 , in response to detecting the input, may begin playing back, in synchrony with playback devices  114  and  118 , the media that playback devices  114  and  118  are already playing back. 
     In another example, in response to detecting the input the first playback device may determine a zone that includes the second playback device so that the first playback device may form a zone with the second playback device. For instance, the first playback device may determine, among playback devices representing zones that are detectable by the first playback device, a zone that includes the second playback device. The second playback device may have a highest signal strength detected by the first playback device, perhaps indicating that the second playback device is in closest proximity to the first playback device among the detectable playback devices. In one example, the first playback device may compare only signal strengths of playback devices that are zone coordinators, since the first playback device may receive media from a group coordinator of a zone that the first playback device joins. 
     Alternatively or additionally, the first playback device may determine that the second playback device (or a zone including the second playback device) has a most recent interaction time. A most recent interaction time of a playback device could represent a time when a playback device last detected input or provided playback of media. A most recent interaction time of a zone may represent a time when any playback device of the zone last detected input. 
     The first playback device may also determine the zone that includes the second playback device based on an order in which the first playback device was last included in various zones. Other example criteria for determining the zone that includes the second playback device are possible. 
     In various situations, the first playback device may form the zone with the second playback device without providing indications of multiple potential zones for the first playback device to join. That is, once the input is received at the control interface, the first playback device may automatically determine the zone that includes the second playback device and form the zone with the second playback device without receiving or detecting other inputs. 
     However in other situations, prior to receiving the input the control interface of the first playback device may provide (i) an indication of a zone that includes the second playback device, (ii) an indication of the second playback device, or (iii) an indication of media being played back by the second playback device or being played back by other playback devices of the zone that includes the second playback device. 
     As an example, the control interface of the first playback device (or another portion of the first playback device) may include speakers (e.g., speakers  212  of  FIG.  2   ) that provide (i) an audio indication of a zone that includes the second playback device, (ii) an audio indication of the second playback device, and/or (iii) an audio indication of media being played back by the second playback device or being played back by other playback devices of the zone that includes the second playback device. For instance, the first playback device could be playback device  116  in the bathroom of  FIG.  1   , and the control interface of playback device  116  may provide an audio indication that sounds like speech indicating the second playback device  118  (e.g., “Device  2 ”) or the Office zone (e.g., “Office”). Or, playback device  118  could be playing back media that includes Song A by Artist B and the indication provided by the control interface of playback device  116  may indicate, in audio form, that the second playback device  118  is playing back Song A by Artist B. Alternatively or additionally, the control interface may provide as the indication playback of an audio or visual sample of the media that is being played back by the second playback device  118 . Other examples of audio indications are possible. 
     As a further example, the control interface may include a display screen (e.g. touchscreen  520  of  FIG.  5 C ) that provides (i) a visual indication of a zone that includes the second playback device, (ii) a visual indication of the second playback device, or (iii) a visual indication of media being played back by the second playback device or being played back by other playback devices of the zone that includes the second playback device. For instance, the first playback device may be playback device  116  in the bathroom of  FIG.  1   , and the control interface of playback device  116  may display text or icons indicating the second playback device  118  (e.g., “Device  2 ”) or the Office zone (e.g., “Office”). Or, playback device  118  could be playing back media that includes Song A by Artist B and the indication displayed by the control interface of playback device  116  may include text or an icon that indicates the second playback device  118  is playing back Song A by Artist B. Alternatively or additionally, the control interface may display, as the indication, a visual sample of the media that is currently being played back by the second playback device  118 . Other examples of visual indications are possible. 
     An audio or video indication of media being played back by the second playback device  118  may provide information to a user so that the user may decide whether to have the playback device  116  form a zone with the playback device  118  for synchronous playback of the media the playback device  118  is playing back. Audio and visual indications of media being played back may be provided simultaneously by the first playback device. 
     In some examples, the detected input is a second input preceded by a first input that is also received or detected at the control interface of the first playback device. According to such an example, the first input may be a touch-and-hold input to the control interface of the first playback device and the second input may include a release of the control interface. The first input may indicate a command for the first playback device to indicate a potential zone for the first playback device to join. In an example where the playback device  116  is only in communication with the playback device  118 , the playback device  116  may determine that, in response to detecting a first input, the playback device  116  will indicate the zone “Office” or indicate the playback device  118 . After making the determination, the playback device  116  may provide the indication of the determined zone as a potential zone for the first playback device to join. 
     In an example where the first playback device is included in a multi-zone environment (e.g.,  FIG.  1   ), the first playback device may determine multiple zones to indicate in response to detecting the first input. For instance, the first playback device may have stored in memory (e.g., memory  206  of  FIG.  2   ) data representing signal strengths corresponding to respective zones or may detect or receive new signal strengths in response to detecting the first input. The first playback device could be playback device  122  in the master bedroom of  FIG.  1    and may have stored in memory data representing signal strengths (possibly detected by playback device  122 ) of playback device  112  of the dining room zone, playback device  114  of the kitchen zone, and/or playback devices  128  and  120  of the bedroom zone. The first playback device  122  may determine the sequence of zones to indicate in order of increasing or decreasing signal strengths. As an illustration, the first playback device  122  may determine the sequence of zones to be indicated as (i) the bedroom zone represented by playback devices  128  and  120 , (ii) the kitchen zone represented by playback device  114 , and (iii) the dining room zone represented by playback device  112 , corresponding to respective signal strengths detected by the first playback device  122 . So, in response to detecting the touch-and-hold input at the control interface, the first playback device  122  may sequentially (and perhaps repetitively) indicate the respective playback zones according to the determined sequence until the second (e.g., release) input is detected. Then, in response to detecting the second input, the first playback device  122  may join the zone indicated by the control interface when the second input was detected. 
     In another instance, the first playback device  122 , may determine the sequence of zones to indicate in order of most recent user interaction times of the respective zones. The first playback device may have stored in memory (e.g., memory  206  of  FIG.  2   ) data representing most recent user interaction times corresponding to respective zones (e.g., timestamp data). As one example, a most recent interaction time could include a time when input was last provided to a playback device of the zone or when a playback device of the zone last provided playback of media. For instance, the first playback device could be playback device  122  of  FIG.  1    and may have stored in memory data representing most recent interaction times of playback device  112  of the dining room zone, playback device  114  of the kitchen zone, and/or playback devices  128  and  120  of the bedroom zone. The first playback device  122  may determine the sequence of zones to indicate in chronological or reverse chronological order with respect to most recent interaction times of the zones. As an illustration, playback device  122  may determine the sequence of zones to be indicated as (i) the kitchen zone represented by playback device  114 , (ii) the dining room zone represented by playback device  112 , and iii) the bedroom zone represented by playback devices  128  and  120 , corresponding to respective most recent user interaction times stored by the first playback device  122 . 
     As discussed above, the first playback device may also determine the sequence of zones to indicate in an order in which the first playback device was last included in zones with other playback devices. The first playback device may have stored in memory (e.g., memory  206  of  FIG.  2   ) data representing times when the first playback device was last included in zones with various playback devices (e.g., timestamp data). For instance, the first playback device could be playback device  122  of  FIG.  1    and may have stored in memory data representing times (i) the first playback device  122  was last included in a zone with playback device  112 , (ii) the first playback device  122  was last included in a zone with playback device  114 , and/or (iii) the first playback device  122  was last included in a zone with the playback devices  120  and  128 . The first playback device  122  may determine the sequence of zones to indicate in chronological or reverse chronological order with respect to the times corresponding to the zones. As an illustration, playback device  122  may determine the sequence of zones to be indicated as (i) the kitchen zone represented by playback device  114 , (ii) the dining room zone represented by playback device  112 , and (iii) the bedroom zone represented by playback devices  128  and  120 . 
     In this instance the first playback device may, in response to detecting the touch-and-hold input at the control interface, sequentially (perhaps repetitively) indicate the respective playback zones according to the determined sequence until the second (e.g., release) input is detected. In response to detecting the second input, the first playback device may join the zone that was last indicated by the control interface when the second input was detected. 
     In another case, the first playback device may detect an input indicating a command for the first playback device to remain within the first zone and resume playback of media associated with the first zone. In this case, detecting the first input may cause playback devices of the first zone to pause media playback while potential zones for the first playback device to join are indicated by the control interface of the first playback device. Upon detecting the input indicating a command to remain within the first zone and resume playback of media associated with the first zone, the first playback device may resume media playback using a stored file offset or a track time corresponding to a point in the media where playback was paused. 
     At block  504 , the method includes based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to playback the media in synchrony with the at least one second playback device. For example, causing the first playback device to playback media in synchrony with the at least one second playback device may include the first playback device receiving the media from the second playback device. The second playback device may send the media to the first playback device in response to the first playback device sending to the second playback device an indication of the command to form the zone and playback the media in synchrony. Row A of  FIG.  6    illustrates one example of block  504  conceptually by showing, at time t 1  (shortly before the first playback device detects the input indicating a command to form the zone with at least the second playback device), a first playback device within a first zone and a second playback device within a second zone, and at time t 2  (shortly after the first playback device detects the input indicating the command to form the zone with at least the second playback device), the first and second playback devices being included in a single zone for synchronous playback of the media. 
     In some instances, before detecting the input, the first playback device may be included in a first zone that also includes a third playback device. In response to detecting the input, the first playback device may cause the third playback device to play back the media in synchrony with the first and second playback devices (i.e., the third playback device joins the zone with the first playback device). Row B of  FIG.  6    depicts this example conceptually by depicting, at time t 1 , a first playback device and a third playback device within a first zone and a second playback device within a second zone, and at time t 2 , the first, second, and third playback devices being included in a single zone for synchronous playback of the media. 
     In the example shown with respect to Row B, the first playback device may be a zone coordinator of the first zone prior to forming the zone with the second playback device. As the zone coordinator, the first playback device may control or communicate with other playback devices of the first zone in various ways. For instance, the zone coordinator may provide media and/or timing information to other playback devices of the zone. Alternatively the third playback device may be the zone coordinator of the first zone. Either the first playback device or the third playback device can determine the zone that the first and third playback devices may join. Alternatively, either playback device can communicate with the second playback device (or a zone coordinator of the second zone) to facilitate the first and third playback devices joining the second zone. 
     In a situation depicted in Row C of  FIG.  6   , prior to detecting the input at the control interface (e.g., at time t 1 ), the first playback device may be included in a first zone with a third playback device and the second playback device may be within a second zone. In response to the detected input, the first and second playback devices may form a zone and playback the (first) media in synchrony, but the first playback device may cause the third playback device to playback a second media while the first and second playback devices playback the first media in synchrony (e.g., at time t 2 ). That is, the input indicates a command for the first playback device to leave the first zone to join the second zone and consequently the third playback device remains in the first zone. 
     Prior to the first playback device leaving the first zone that includes the third playback device to form a zone with the second playback device, the first playback device may act a zone coordinator of the first zone. But when the first playback device leaves the first zone, the first playback device may cause the third playback device to become a (new) zone coordinator of the first zone. The first playback device may determine the third playback device to become the zone coordinator of the first zone based on respective signal strengths of playback devices of the first zone detected by the third playback device. That is, the third playback device may detect the signal strengths of various playback devices of the first zone and send signal strength data to the first playback device so that the first playback device can determine the new zone coordinator. In another example, the first playback device may determine which of various playback devices of the first zone has a strongest communication link to playback devices of the second zone (e.g., average signal strengths of playback devices of the second zone detected by playback devices of the first zone), and cause the playback device of the first zone with the strongest communication link to the second zone to become a (new) zone coordinator of the second playback zone. By way of example, the third playback device, of any remaining playback device of the first zone, may be most centrally located within the first zone and best suited to control the playback devices of the first zone. In this way, the new zone coordinator of the first zone may be determined based on the new zone coordinator&#39;s capability to effectively communicate with other playback devices of the first zone. 
     So that the first playback device may determine the third playback device to be a new zone coordinator, data representing various states of playback devices may be stored in a table within a memory (e.g., memory  206  of  FIG.  2   ) of the first playback device, or another playback device that is in communication with the first playback device. The playback device storing the data may share the data with other playback devices via UPnP (Universal Plug and Play) protocols and may update the stored data in response to state changes of the media playback devices (e.g., a playback device leaving or joining a zone, starting or stopping playback of media, or becoming or ceasing to be a zone coordinator). For example, such a table could be a data array with rows representing various playback devices and columns representing data such as (i) a zone identifier indicating the zone of a corresponding playback device, (ii) a bit indicating whether or not the corresponding playback device is a zone coordinator of the indicated zone (an ungrouped playback device may be a zone coordinator by default), and (iii) whether the corresponding playback device (i.e., a corresponding playback zone) is currently playing back media, among other possibilities. In other examples, a playback device may query another playback device (e.g., a zone coordinator) for such information as needed. 
     In another example, the first and third playback devices may be a bonded pair (or bonded zone) that functions, for example, as a left stereo playback device that plays a left channel of media and a right stereo playback device that plays a right channel of media. Another example of a bonded pair may include any two playback devices that are permanently grouped or paired to act in unison as a single playback device. After forming the zone with the second playback device, the first playback device may play back a first stereo portion of the media and the third playback device may play back a second stereo portion of the media being played back by the second playback device. Also, as depicted in Row D of  FIG.  6   , prior to detecting the input (e.g., time t 1 ) the bonded pair that includes the first and third playback devices could be included in a first zone that further includes a fourth playback device. In response to the detected input (as shown at time t 2 ), the first, second, third, and fourth playback devices may playback the media in synchrony as a zone. However, as shown in Row E of  FIG.  6   , it is also possible that the fourth playback device remains in the first zone to play a second media as the first and third playback devices form the zone with the second playback device. 
     In another example, when the input is received at the control interface of the first playback device, there may be no other playback devices or zones engaging in playback of media. Here, it is possible the input either has no effect on the first playback device, or the input may cause the first playback device to form a zone with the second playback device such that when playback of media is initiated in the second zone, the first playback device will then join the second playback device in synchronous playback of the media. 
     In yet another example, the input received by the control interface of the first playback device may cause the first playback device to form a zone with all other playback devices that are in communication with or associated with the first playback device for playback of a given media. For example, the received input could cause playback device  102  to join with all other playback devices depicted in  FIG.  1    for synchronous playback of a common media. 
     Method  700  shown in  FIG.  7    presents an example method that can be implemented within an operating environment involving, for example, the media playback system  100  of  FIG.  1    and one or more of the playback device  200  of  FIG.  2   . Method  700  may include one or more operations, functions, or actions as illustrated by one or more of blocks  702  and  704 . Although the blocks are illustrated in sequential order, these blocks may also be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon the desired implementation. 
     In addition, for the method  700  and other processes and methods disclosed herein, the flowchart shows functionality and operation of one possible implementation of present embodiments. In this regard, each block may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor for implementing specific logical functions or steps in the process. The program code may be stored on any type of computer readable medium, for example, such as a storage device including a disk or hard drive. The computer readable medium may include non-transitory computer readable medium, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device. In addition, for the method  700  and other processes and methods disclosed herein, each block in  FIG.  7    may represent circuitry that is wired to perform the specific logical functions in the process. 
     At block  702 , the method includes detecting, by a control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) playback the media in synchrony with the at least one first playback device. The control device is communicatively coupled to the second playback device but not necessarily communicatively coupled to the first playback device. That is, the control device may be a bonded controller. Detecting the input may involve receiving the input at the control device. 
     In some examples, the bonded controller is a portable device that includes a control interface, a processor, data storage, and/or a communication interface. The bonded controller may be configured to communicate, via the communication interface, with a single playback device (or a bonded zone of playback devices) via infrared, Bluetooth, WIFI, or other commonly known wireless communication protocols. The control interface may include any mechanism for input such as a key, a knob, a dial, a push-button, a soft key, a combination of different keys, and so on. By way of illustration, the bonded controller can be placed in a room associated with a playback device or bonded zone with which the bonded controller is bonded. 
       FIG.  8    depicts an example bonded controller  800 . The bonded controller  800  may be bonded to a first playback device (or a bonded zone including the first playback device) and include several push-buttons. For example, receiving input at push-button  830  may cause the first playback device (and/or other playback devices in the first zone) to form the zone with at least the second playback device. Receiving input at push-button  832  may cause the first playback device (and/or other playback devices in the first zone) to advance through a playback queue in a first direction, receiving input at push-button  834  may cause the first playback device (and/or other playback devices in the first zone) to begin playback of media, receiving input at push-button  836  may cause the first playback device (and/or other playback devices in the first zone) to pause playback of media, and receiving input at push-button  838  may cause the first playback device (and/or other playback devices in the first zone) to advance through a playback queue in a second direction, Receiving input at push-button  840  may initiate a process for causing the bonded controller to become bonded to another playback device or another bonded zone. In some examples, the bonded controller  800  may also have any control interface features depicted in  FIGS.  5 B- 5 D . 
     Referring back to  FIG.  7   , at block  704  the method includes, based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to playback the media in synchrony with the at least one first playback device. 
     One of ordinary skill in the art will appreciate that all functionality described above in relation to method  600  may be similarly applied to method  700 . While method  600  describes functions being performed in response to receiving or detecting one or more inputs at a control interface of a first playback device, method  700  may differ only in that the one or more inputs may be received or detected at a control device (e.g., a bonded controller) that is communicatively coupled to only one playback device. 
     One of skill in the art will also appreciate that while this disclosure provides examples of media playback devices that interact with each other in response to provided inputs, similar interactions could take place in other areas of home or office automation. For example, an input could be detected at a dishwasher, causing the dishwasher to assume a common operation schedule (i.e., form a zone) with a washer and a dryer. This could cause the dishwasher to turn on or turn off in synchrony with the washer and/or dryer, to consume electricity at off-peak hours, for example. Or as another example, an input could be detected at a control interface of a lighting module in a living room, causing the lighting module to form a zone with a lighting module in a kitchen, thereby causing the lighting module in the living room to assume an operation schedule of the lighting module in the kitchen. This may cause the lighting modules to turn on/off and/or dim according to a common schedule. Other examples are possible. 
     IV. Conclusion 
     The description above discloses, among other things, various example systems, methods, apparatus, and articles of manufacture including, among other components, firmware and/or software executed on hardware. It is understood that such examples are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of the firmware, hardware, and/or software aspects or components can be embodied exclusively in hardware, exclusively in software, exclusively in firmware, or in any combination of hardware, software, and/or firmware. Accordingly, the examples provided are not the only way(s) to implement such systems, methods, apparatus, and/or articles of manufacture. 
     Examples described herein involve, among other things, detecting an input at a control interface or a bonded controller of a first playback device so that the first playback device (i) forms a zone with a second playback device that is already playing back media and (ii) plays back the media in synchrony with the at least one second playback device. Other aspects of the examples will be made apparent in the remainder of the description herein. 
     In one aspect, a method is provided. The method involves detecting, via a control interface of a first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) play back the media in synchrony with the at least one second playback device and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to play back the media in synchrony with the at least one second playback device. 
     In another aspect, a first playback device is provided. The first playback device includes a processor and memory storing instructions that when executed by the first playback device, cause the first playback device to perform functions. The functions include detecting, via a control interface of the first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) play back the media in synchrony with the at least one second playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to play back the media in synchrony with the at least one second playback device. 
     In yet another aspect, a non-transitory computer readable memory is provided. The non-transitory computer readable memory has stored thereon instructions executable by a first playback device to cause the first playback device to perform functions. The functions include detecting, via a control interface of the first playback device while at least one second playback device is playing media, an input indicating a command for the first playback device to (i) form a zone with the second playback device and (ii) play back the media in synchrony with the at least one second playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the first playback device to play back the media in synchrony with the at least one second playback device. 
     In another aspect, a method is provided. The method involves detecting, by a control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) play back the media in synchrony with the at least one first playback device, wherein the control device is communicatively coupled to the second playback device and not communicatively coupled to the first playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to play back the media in synchrony with the at least one first playback device. 
     In another aspect, a control device is provided. The control device includes a processor and memory storing instructions that when executed by the control device, cause the control device to perform functions. The functions include detecting, by the control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) play back the media in synchrony with the at least one first playback device, wherein the control device is communicatively coupled to the second playback device and not communicatively coupled to the first playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to play back the media in synchrony with the at least one first playback device. 
     In yet another aspect, a non-transitory computer readable memory is provided. The non-transitory computer readable memory has stored thereon instructions executable by a control device to perform functions. The functions include detecting, by the control device while at least one first playback device is playing media, an input indicating a command for a second playback device to (i) form a zone with the first playback device and (ii) play back the media in synchrony with the at least one first playback device, wherein the control device is communicatively coupled to the second playback device and not communicatively coupled to the first playback device; and based on the detected input, causing (i) the first playback device and the second playback device to form the zone and (ii) the second playback device to play back the media in synchrony with the at least one first playback device. 
     Additionally, references herein to “embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one example embodiment of an invention. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. As such, the embodiments described herein, explicitly and implicitly understood by one skilled in the art, can be combined with other embodiments. 
     The specification is presented largely in terms of illustrative environments, systems, procedures, steps, logic blocks, processing, and other symbolic representations that directly or indirectly resemble the operations of data processing devices coupled to networks. These process descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, it is understood to those skilled in the art that certain embodiments of the present disclosure can be practiced without certain, specific details. In other instances, well known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the embodiments. Accordingly, the scope of the present disclosure is defined by the appended claims rather than the forgoing description of embodiments. 
     When any of the appended claims are read to cover a purely software and/or firmware implementation, at least one of the elements in at least one example is hereby expressly defined to include a tangible, non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on, storing the software and/or firmware.