A method for a media playback system, the method comprising: receiving, at a first playback device (102-132) of the media playback system , a user input to adjust a volume; in response to receiving the user input, determining, at the first playback device (102-132), whether the first playback device is included in a bonded zone, wherein a bonded zone comprises a plurality of playback devices (102-132) that are grouped for synchronous playback of audio content; if it is determined that the first playback device is not included in a bonded zone, applying the received user input to the first playback device; if it is determined that the first playback device is included in a bonded zone, determining if the first playback device is a secondary device ; if it is determined that the first playback device is included in a bonded zone and is a secondary device, wherein a second playback device is the primary playback device of the bonded zone, sending, over a network from the first playback device to the second playback device of the bonded zone, a first message including information based on the user input at the first playback device; after sending the first message, determining, by the second playback device, based on the information in the first message, an adjusted volume for each of the plurality of playback devices of the bonded zone; after determining the adjusted volume, sending, from the second playback device to the first playback device over the network, a second message including information for an adjusted volume of the first playback device; receiving, at the first playback device, the second message; and playing back audio based on the information for the adjusted volume of the first playback device included in the second message. receiving, at a first playback device (102-132) of the media playback system , a user input to adjust a volume; in response to receiving the user input, determining, at the first playback device (102-132), whether the first playback device is included in a bonded zone, wherein a bonded zone comprises a plurality of playback devices (102-132) that are grouped for synchronous playback of audio content; if it is determined that the first playback device is not included in a bonded zone, applying the received user input to the first playback device; if it is determined that the first playback device is included in a bonded zone, determining if the first playback device is a secondary device ; if it is determined that the first playback device is included in a bonded zone and is a secondary device, wherein a second playback device is the primary playback device of the bonded zone, sending, over a network from the first playback device to the second playback device of the bonded zone, a first message including information based on the user input at the first playback device; after sending the first message, determining, by the second playback device, based on the information in the first message, an adjusted volume for each of the plurality of playback devices of the bonded zone; after determining the adjusted volume, sending, from the second playback device to the first playback device over the network, a second message including information for an adjusted volume of the first playback device; receiving, at the first playback device, the second message; and playing back audio based on the information for the adjusted volume of the first playback device included in the second message. <EOS>