Abstract:
The present invention provides a method for automatically tuning a stringed instrument including the steps of inducing a signal on a string under tension to generate a resonance signal having an amplitude from the string and adjusting tension of the string in response to the amplitude of the resonance signal. The present invention also provides a system for automatically tuning a stringed instrument including a string, tensioning means operably attached to one end of the string for tensioning the string, and a processor for driving the tensioning means to induce a signal on the string and generate a resonance signal having an amplitude from the string and for adjusting tension of the string in response to the amplitude of the resonance signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/187,597 filed Mar. 7, 2000. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a method and system for automatically tuning a stringed instrument. 
     BACKGROUND OF THE INVENTION 
     All stringed musical instruments require tuning due to changes in physical conditions or changes in the characteristics of the materials from which the instruments are made. Many stringed instruments, such as guitars, drift out of tune quite rapidly and musicians often need to make tuning adjustments during the course of normal use. Systems for automatically tuning a stringed instrument are known, however, such prior art systems have many shortcomings. Prior art automatic tuning systems are relatively large in size and, thus, can not be retrofitted to some instruments. When assembled to an instrument, the size of prior art systems often detracts from the original aesthetics of the instrument. Further, the installation of prior art systems to an instrument distorts the original tonal qualities of the instrument. Prior art systems also consume large amounts of power and, thus, require large power supplies which must be located remotely from the instrument. Additionally, prior art automatic tuning systems tune the instrument via complex signal frequency means or less accurate string tension means. Accordingly, there is a desire for an improved automatic tuning system for a stringed instrument. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method for automatically tuning a stringed instrument including the steps of inducing a signal on a string under tension to generate a resonance signal having an amplitude from the string and adjusting tension of the string in response to the amplitude of the resonance signal. The present invention also provides a system for automatically tuning a stringed instrument including a string, tensioning means operably attached to one end of the string for tensioning the string, and a processor for driving the tensioning means to induce a signal on the string and generate a resonance signal having an amplitude from the string and for adjusting tension of the string in response to the amplitude of the resonance signal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
     FIG. 1 is a schematic of an automatic tuning system for a stringed instrument in accordance with the present invention; 
     FIG. 2 is a schematic, cross-sectional view of one embodiment of a linear motor for use in the present invention; 
     FIG. 3 is a perspective view of internal components of the linear motor in FIG. 2; 
     FIGS. 4A-4G are a series of schematics illustrating an operation of the linear motor of FIGS. 2 and 3 for moving a rod in one direction; 
     FIG. 5 is a cross-sectional view of one embodiment of an actuator for use in the linear motor; and 
     FIGS. 6A-6D illustrate a signal modulation technique used to drive the actuators in the linear motor. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a schematic of an automatic tuning system  10  in accordance with the present invention. The automatic tuning system  10  can be adapted to adjust the tension of a wide variety of structures including, but not limited to, wires, cables, strings, or the like. Further, the automatic tuning system  10  is particularly designed to adjust such structures to a predetermined response. 
     In one embodiment, the system  10  is adapted for tuning any stringed instrument, such as a bass, piano, or violin, etc. More specifically, this embodiment of the system  10  is designed to automatically and simultaneously tune one or more strings of an instrument. By way of example and not limitation, the components and operation of the automatic tuning system  10  are described in relation to the tuning of an electric guitar  12  having a body  14 , one or more strings  16 , and a manual tuner  18  for each string  16 . Each string  16  and each manual tuner  18  is secured to the body  14  of the guitar  12 . To “play” the guitar  12 , a user or musician strums or stretches the guitar strings  16  thereby creating string vibrations. 
     The automatic tuning system  10  includes one or more audio input transducers  20  which produce electrical analog signals in response to the string vibrations. Many types of guitars include one or more audio input transducers which are integral to the guitar. With such guitars, the integrated audio input transducers may be used to provide the analog signals to the automatic tuning system  10 . With the remaining guitars, one or more audio input transducers may be retrofitted to the guitar. 
     The automatic tuning system  10  also includes a signal interface  22 . The analog signals produced by the one or more audio input transducers  20  are transmitted through a transducer output channel  24  to the signal interface  22 . The signal interface  22  is designed to route and condition the analog signals for processing within the automatic tuning system  10 . The signal interface  22  includes a signal muting circuit  26 , a signal conditioning circuit  28 , and an ADC (analog to digital converter)  30 . Each analog signal produced by the one or more audio input transducers  20  is transmitted to both the signal muting circuit  26  and the signal conditioning circuit  28 . 
     During normal play, each analog signal is transmitted from the signal muting circuit  26  through an amplifier output channel  32  to an audio amplifier  34 . The audio amplifier  34  amplifies each analog signal received and produces an electrical signal which when input to an appropriate audio transducer  36 , such as a speaker, creates audible sounds. In this manner, the string vibrations created when the musician strums or stretches the strings  16  are transformed into amplified music. One of ordinary skill in the art will recognize that the present invention can be practiced without the audio amplification described above. 
     When the guitar  12  is being automatically tuned by the system  10 , the signal muting circuit  26  is designed to prevent the transmission of all analog signals to the amplifier output channel  32  and, in turn, to the audio amplifier  34 . In other words, the signal muting circuit  26  mutes the output of the guitar  12  during automatic tuning of the guitar strings  16 . This signal muting operation can optionally be disabled. 
     The signal conditioning circuit  28  includes one or more signal amplifiers and signal filters to condition each analog signal from the one or more audio input transducers  20  for optimal input to the ADC  30 . The ADC  30  converts each analog signal into a digital signal. Each digital signal is generated in a predetermined data format, such as a multi-bit linear code or other such structure, suitable for digital signal processing. 
     The automatic tuning system  10  further includes a processor  38  having a central processing unit (CPU)  40 , memory  42 , and digital signal processing capabilities  44 . The types of digital signal processing which may be used in the present invention include, but are not limited to, lowpass filters, bandpass filters, highpass filters, demultiplexing and fast fourier transforms. The processor  38  is also capable of standard two-way communications. Two-way communications between the processor  38  and a remotely located computer  46  are transmitted through an external interface  48  as described in greater detail below. 
     In one embodiment, a signal conditioning circuit  28 , an ADC  30 , and a processor  38  are dedicated to each string  16  of the guitar  12  to be tuned. One of ordinary skill in the art will recognize that there are a variety of alternative embodiments employing signal multiplexing or other means to eliminate the need for a separate signal conditioning circuit  28  and/or ADC  30  and/or processor  38  for each string  16 . These embodiments allow a trade-off between tuning speed and accuracy versus electronic complexity, size, and cost. 
     The automatic tuning system  10  also includes an actuator driver  50  controlled by the processor  38 . The actuator driver  50  includes a power supply  52 , one or more driver circuits  54 , and a motor  56  for each driver circuit  54 . Each driver circuit  54  is coupled with a separate motor  56  via an actuator output channel  58 . Each guitar string  16  is also connected to a separate motor  56 . Each driver circuit  54  is controlled by the processor  38  to operate or move the respective motor  56 . The operation of each motor  56  either tautens (tightens) or slackens (loosens) the respective guitar string  16 . In other words, each driver circuit  54  is controlled by the processor  38  to operate the respective motor  56  to increase or decrease the tension of a particular guitar string  16 . 
     The operation or response of a motor  56  is controlled by the type of input voltage drive profile supplied to the motor  56  by the driver circuit  54 . In other words, the drive profile of the input voltage signal supplied to a motor  56  by a driver circuit  54  controls the operation or response of the motor  56 . There are various types of driver circuits and, thus, drive profiles commercially available. Accordingly, one of ordinary skill in the art may select from several input voltage drive profiles each of which produces a different motor response. 
     The automatic tuning system  10  further includes a plurality of user interfaces, preferably a manual switch interface  60  and an external interface  48 . The manual switch interface  60  provides a user with a manual input means at the body  14  of the guitar  12 . The manual switch interface  60  is composed of tuning selector means, tuning actuation means, tuning learning means, communications means to a remote computer  46 , and mute disable means. Upon activation of the tuning actuation means, the processor  38  retrieves codes from the processor memory  42  which represent a previously stored string tuning pattern. The processor  38  then uses these codes to automatically produce said tuning pattern across the strings  16  on the guitar  12 . The processor  38  uses the setting in the tuning selector means to determine which of a plurality of pre-stored tuning pattern codes to use for the tuning process. In like fashion, activation of the learning means causes the processor  38  to store tuning pattern codes in the processor memory  42 . Upon activation of the learning means, the processor  38  stores the tuning pattern codes into the processor memory location indicated by the tuning selector means. Upon activation of the mute disable means, muting of the signal to the audio amplifier  34  is disabled and the signal generated by the strings  16  can be heard through the audio transducer  36 . 
     One embodiment of the manual switch interface  60  in includes a multi-position rotary selector switch and three or more push-button switches. An alternative embodiment uses an electronic display with touch screen capability. These embodiments of the manual switch interface  60  are illustrative only. Various alternatives and modifications are well known to those of ordinary skill in the art. 
     The external interface  48  is preferably the type of interface typically associated with a personal computer. Preferably, the external interface  48  is a MIDI (Music Instrument Data Interface) type interface as commonly known and accepted in the music industry. Alternatively, the external interface  48  can be a standard RS232 type interface. One function of the external interface  48  is to couple the processor  38  to a floor switch box  62  thus providing second manual switching means, similar to the manual switch interface  60 , for selecting preset string tension patterns. Another function of the external interface  48  is to couple the processor  38  to a computer  46  for the purpose of programming one or more string tension patterns into the system  10  and for providing third manual switching means, similar to the manual switch interface  60 , for selecting preset string tension patterns. Preferably, the processor  38  is programmable and, as such, one of ordinary skill in the art could program the functionality of the interfaces  60  and  48  in a plurality of ways. One of ordinary skill in the art will recognize that the present invention can be practiced without the computer  46  and/or the floor switch  62 . 
     The automatic tuning system  10  is designed to be installed or assembled as an original component of the guitar  12 . Alternatively, the system  10  can be retrofitted to an existing guitar. As either an original or retrofit component, the system  10  has been adapted to preserve the original tonal qualities of the guitar  12 . 
     The signal interface  22 , the processor  38 , and the actuator driver  50  are contained in a case  64  packaged to the body  14  of the guitar  12 . The motors  56  are located or packaged adjacent to the ends of the guitar strings  16  opposite the manual tuners  18 . As such, the automatic tuning system  10  does not effect or alter the typical mechanics associated with playing the guitar  12 . 
     FIG. 2 is a schematic, cross-sectional view of a linear motor  56  for use in the present invention, showing the internal components of the linear motor  56 . The linear motor  56  is shown in schematic illustration for descriptive purposes. The linear motor  56  is encased in a housing  66 . The housing  66  is designed to protect the linear motor  56 . The linear motor  56  is assembled to the body  14  of the guitar  12 . In this embodiment, the linear motor  56  so attached is capable of moving a rod  68 , having any cross-sectional shape, in either direction along axis A in FIG.  2 . In other words, the fixed linear motor  56  is capable of moving the rod  68  left or right relative to the linear motor  56  as illustrated in FIG.  2 . To accomplish this movement, the linear motor  56  operates in a walking beam feeder fashion, shown in FIG.  4  and described in greater detail below. To perform the walking beam feeder movement, the linear motor  56  includes three piezo or piezoelectric actuators  70   a,    70   b,  and  70   c  (piezo actuator  70   a  and  70   c  are shown in FIG.  3 ), a pair of clamps  72  and  74 , and a resilient means  76 . The first clamp  72  is fixed to the housing  66  and the second clamp  74  is free from the housing  66 . In alternative embodiments of the present invention, the resilient means  76  may comprise an actuator retractor spring (as shown in FIG.  2 ), an o-ring or other similar type of resilient structure, or another piezo actuator. The resilient means  76  is disposed between the second clamp  74  and the housing  66 . The linear motor  56  further includes an electrical connector (not shown in FIG. 2) for receiving power to operate of the linear motor  56 . 
     FIG. 3 is a perspective view of selected internal components of the linear motor  56  used to accomplish the walking beam feeder movement. The two clamps  72  and  74  are adapted to clamp or hold the rod  68 . The axis of the rod  68  is aligned perpendicular to the two clamps  72  and  74 . The rod  68  is disposed within the jaws of the two clamps  72  and  74 . In the present embodiment, a musical string  16  is secured to the end  80  of the rod  68  adjacent to the first clamp  72 . In alternative embodiments, a flexible structure, such as a cable, wire or the like can be secured to the end  80  of the rod  68  adjacent to the first clamp  72 . 
     The two outermost actuators  70   a  and  70   c  are operated between an energized state, wherein voltage is applied to the actuator, and a de-energized state, wherein no voltage is applied to the actuator. The two outermost actuators  70   a  and  70   c  are normally de-energized. When the first actuator  70   a  is de-energized, the first clamp  72  is closed, or clamps to or engages the rod  68 . When the third actuator  70   c  is de-energized, the second clamp  74  is closed, or clamps to or engages the rod  68 . 
     Each of the three actuators  70   a-c  is energized by applying a voltage to the respective actuator. Energizing the first actuator  70   a  disengages the first clamp  72  from the rod  68 . Energizing the third actuator  70   c  disengages the second clamp  74  from the rod  68 . In other words, energizing the first actuator  70   a  opens the first clamp  72  thereby releasing the rod  68  and energizing the third actuator  70   c  opens the second clamp  74  thereby releasing the rod  68 . 
     The second or central actuator  70   b  is disposed between the first and second clamps  72  and  74  providing a nominal displacement between the first and second clamps  72  and  74 . When energized, the second actuator  70   b  provides an increase in the displacement between the two clamps  72  and  74 . In other words, when energized, the second actuator  70   b  provides an expansion force which pushes the two clamps  72  and  74  apart or away from each other. Within the normal or typical operating voltage range, the amount of increase in the displacement between the two clamps  72  and  74  is proportional to the amount of voltage applied across the second actuator  70   b.    
     When de-energized, the second actuator  70   b  provides a decrease in the displacement between the two clamps  72  and  74 . Piezo actuators, especially piezo stacks, provide a contraction force significantly lower or weaker than the aforementioned expansion force and are susceptible to failure caused by tension during contraction. Accordingly, the resilient means  76  is adapted to bias or push the second clamp  74  toward the second actuator  70   b.  In alternative embodiments, the resilient means  76  can provide all or part of the force necessary to move the two clamps  72  and  74  back to the nominal displacement. 
     The operation of the three actuators  70   a-c  may be sequenced to move the rod  68  in one direction or the opposite direction along axis A of the rod  68 . FIGS. 4A-4G are a series of schematics illustrating an operation of the linear motor  56  for moving the rod  68  in one direction. In other words, FIGS. 4A-4G illustrate a sequence of operations performed by the linear motor  56  to move the rod  68  in a direction of travel as indicated by arrow  82 . 
     FIG. 4A illustrates the linear motor  56  in a first position. The second actuator  70   b  is de-energized and the first and second clamps  72  and  74  are clamped to the rod  68 . The first clamp  72  is fixed to the housing  66  or anchored in a fixed location or to a fixed surface. During the first operation, voltage to each of the three actuators  70   a-c  is switched off and the displacement between the first and second clamps  72  and  74  is nominal. 
     FIG. 4B illustrates the linear motor  56  in a second position. The first clamp  72  is opened by energizing the first actuator  70   a.  During the second operation, the rod  68  is released by the first clamp  72 . 
     FIG. 4C illustrates the linear motor  56  in a third position. A voltage is applied to the second actuator  70   b  thus energizing the second actuator  70   b  and providing an increase in the displacement between the first and second clamps  72  and  74 . During the third operation, the expansion of the second actuator  70   b  forces the second clamp  74  and the rod  68  in a direction of travel as indicated by arrow  82 . 
     Movement of the second clamp  74  compresses the resilient means  76  against the housing  66 . 
     FIG. 4D illustrates the linear motor  56  in a fourth position. The first clamp  72  is closed by de-energizing the first actuator  70   a.  During the fourth operation, the first clamp  72  clamps to the rod  68 . 
     FIG. 4E illustrates the linear motor  56  in a fifth position. The second clamp  74  is opened by energizing the third actuator  70   c.  During the fifth operation, the rod  68  is released by the second clamp  74 . 
     FIG. 4F illustrates the linear motor  56  in a sixth position. The second actuator  70   b  is de-energized. During the sixth operation, the resilient means  76  pushes the second clamp  74  in the direction of travel indicated by arrow  84 . 
     FIG. 4G illustrates the linear motor  56  in a seventh position. The second actuator  70   b  is de-energized and the first and second clamps  72  and  74  are clamped to the rod  68 . During the seventh operation, voltage to each of the three actuators  70   a-c  is switched off and the displacement between the first and second clamps  72  and  74  is nominal. The seventh position is similar to the first position but with the rod  68  moved in the direction of travel as indicated by arrow  82  relative to the linear motor  56 . 
     The linear motor  56  is capable of performing the seven step operational sequence in less than or equal to approximately 400 to 4,000 microseconds. A single cycle of the seven step operational sequence will nominally move or displace the rod  68  approximately 12 micrometers. To move or displace the rod  68  a distance greater than the nominal displacement produced by the second actuator  70   b,  the seven step operational sequence may be repeated or cycled two or more times. To move or displace the rod  68  a distance less than the nominal displacement produced by the second actuator  70   b, the amount of voltage applied to the second actuator  70   b  is reduced proportionally. For example, to move or displace the rod  68  a distance of one-half the nominal displacement produced by the second actuator  70   b,  one-half the nominal voltage is applied to the second actuator  70   b.  To move or displace the rod  80  a distance of one-quarter the nominal displacement produced by the second actuator  70   b,  one-quarter the nominal voltage is applied to the second actuator  70   b.    
     The sequence of operations performed by the linear motor  56  may be modified to move the rod  68  in the direction opposite of arrow  82 . Further, the present invention may be practiced by combining one or more operations into a single step. By moving the rod  68  in opposing directions, the linear motor  56  is capable of tightening or loosening the respective guitar string  16 . In other words, the linear motor  56  can increase or decrease the tension of the guitar string  16 . One of ordinary skill in the art will recognize that other types of linear motors or like structures which are capable of providing tension on a string  16  may also be used within the present invention. 
     FIG. 5 is a cross-sectional view of one embodiment of an actuator  70  for use in the linear motor  56  of the present invention. The actuator  70  is designed to produce a positional or spatial displacement along one predetermined axis when energized. In other words, the cross-section of the actuator  70  is designed to expand along at least one predetermined axis when energized. In one embodiment of the present invention, the actuator  70  includes a ceramic substrate  86  sandwiched between two opposing end caps  88  and  90 . The two end caps  88  and  90  are preferably formed in the shape of truncated cones. In one embodiment of the present invention, the two end caps  88  and  90  are made from sheet metal. Each end cap  88  and  90  includes a contact surface  92  and  94  respectively. In one embodiment of the present invention, the entire periphery of each end cap  88  and  90  is bonded to the ceramic substrate  86 . This type of actuator  70  is commonly referred to in the art as a cymbal actuator. 
     The actuator  70  is operated between a de-energized state, illustrated in FIG. 5 with solid lines, providing a spatial displacement equal to the nominal thickness of the ceramic substrate  86  and the end caps  88  and  90 , and an energized state, illustrated in FIG. 5 with dashed lines, providing a spatial displacement greater than the nominal thickness of the actuator  70 . The actuator  70  is normally de-energized. 
     The actuator  70  is energized by applying a voltage or potential V across the ceramic substrate  86 . The voltage causes the substrate  86  to expand along the Z axis and contract along the X and Y axes as designated in FIG.  5 . As a result, both end caps  88  and  90  flex or bow outwardly from the substrate  86  about flex points  96 ,  98  and  100 ,  102 , respectively. Thus, the contraction of the ceramic substrate  86  shortens the distance between the sidewalls of each end cap  88  and  90  and increases the distance between the contact surfaces  92  and  94 . In this manner, a substantial increase in the displacement between the contact surfaces  92  and  94  is produced. 
     Within the normal or typical operating voltage range, the increase in the displacement between the contact surfaces  92  and  94  for a given cymbal geometry is proportional to the amount of voltage applied across the ceramic substrate  86 . In other words, a nominal voltage produces a nominal displacement, one-half the nominal voltage produces one-half the nominal displacement, one-quarter the nominal voltage produces one-quarter the nominal displacement, etc. 
     The large, flat contact surfaces  92  and  94  of each end cap  88  and  90  render it practical to stack several actuators  70  in order to achieve greater displacements. 
     The present invention may also be practiced with other similar types of actuators including, but not limited to, a single or individual piezoelectric element, a stack of individual piezo elements, a mechanically amplified piezo element or stack, or a multilayer cofired piezo stack. 
     The linear motor  56  has numerous advantages, attributes, and desirable characteristics including, but not limited to, the characteristics listed hereafter. The present invention incorporates relatively simple, inexpensive, low power, reliable controls. More specifically, the linear motor  56  can be powered by a battery. The linear motor  56  is compact in size (i.e. equal to approximately 1 in 3 ) yet physically scalable to dimensions as least as much as a factor of ten greater and highly powerful (i.e. capable of exerting a drive thrust of 35 lbs.). The present invention is highly precise (i.e. capable of producing movement increments of approximately 0.0005 inch), highly efficient (i.e. having an average power consumption of less than 10 Watts when operating and negligible power consumption when idle), and highly reliable (i.e. having a component life expectancy of approximately 250,000,000 cycles). Further, the linear motor  56  produces minimal heat during operation, generates minimal EMI (Electromagnetic Interference) and RFI (Radio-Frequency Interference), and is relatively unaffected by stray EMI and RFI in the area. 
     Additionally, the present invention is capable of producing an accumulated linear travel distance in excess of 2 kilometers. 
     FIG. 6A illustrates an example of a base signal  104  having a frequency. FIG. 6B illustrates an example of a modulation signal  106 . FIG. 6C illustrates an example of a modulated motor movement signal  108  created when the base signal  104  is modulated by the modulation signal  106 . More specifically, the modulated motor movement signal  108  is produced by the processor  38  performing a logical AND function upon the base signal  104  and the modulation signal  106 . The resulting modulated motor movement signal  108  is output from the processor  38  to the drive circuits  54  and then to the motors  56  through the actuator output channel  58 . As a result, the modulated motor movement signal  108  causes the motors  56  to alter the tension of the strings  16  on the guitar  12 . The adjustment or alteration of string tension occurs essentially simultaneously for all strings  16  on the guitar  12  due to the speed of the system  10 . Because the motion of the motors  56  is modulated according to the modulated motor movement signal  108 , a signal is induced on the strings  16  as the strings  16  are adjusted. This induced signal is equivalent to the note to be tuned and its harmonics. As the processor  38  is generating the modulated motor movement signal  108 , the processor  38  is also monitoring a resonance signal  110  generated from the strings  16 . FIG. 6D illustrates an example of a resonance signal  110  generated from a string  16  in response to a signal induced on the string  16  by operation of a motor  56  driven by a modulated motor movement signal  108 . As the strings  16  achieve the selected tuning, the signal induced on the strings  16  by the operation of the motors  56  causes the strings  16  to resonate at a higher amplitude. The processor  38  monitors the varying amplitude of the string resonance and adjusts the modulated motor movement signal  108  to attempt to maximize the amplitude of the string resonance. Practically, the processor  38  may have to overshoot the maximum resonance amplitude to achieve the desired tuning. When the processor  38  detects optimal amplitude from each string  16 , the processor  38  discontinues generating modulated motor movement signals  108  and the tuning process for the guitar  12  is complete. 
     Activation of the tuning process and selection of the specific tuning to be achieved are initiated and determined by operation of the manual switch interface  60 , the foot box  62 , or the remote computer  46  described above. 
     The codes for base signals  104  are stored in the processor memory  42 . The base signals  104  are selected to optimize the results of the modulation and tuning process. 
     The modulation signal  106  for each tuning is developed during the tuning learning process. The tuning learning process is initiated by activation of the tuning learning means described above. The modulation signal codes are stored in processor memory locations determined by the setting of the tuning selector means described above. The first step in the tuning learning process is for the user or musician to manually tune the guitar  12  for the desired sound. Upon completion of the manual tuning, the musician positions the tuning selector means and activates the tuning learning means. Next, the musician strums the strings  16  on the guitar  12 . This action provides a musical signal to the processor  38 . The processor  38  uses the musical signal from each string  16  to develop a modulation signal  106 . The processor  38  then stores the codes for the modulation signal  106  in the processor memory  42 . These stored codes for the modulation signal  106  can be used during a subsequent tuning process by the processor  38  to adjust the tuning of the guitar  12  as described above. 
     In an alternative embodiment, the tunings can be developed and/or stored in a remote computer  46 . The remote computer  46  can be connected to the guitar  12 . The processor  38  may select codes for modulation signals  106  of tunings stored in the remote computer  46 . Upon such selection and electronic transfer of the appropriate codes from the remote computer  46  to the processor  38 , actual tuning of the guitar  12  would occur as described above. In like fashion, codes for a tuning could be electronically transferred from the processor  38  to the remote computer  46 . 
     In yet another embodiment, selection and activation of the tuning process is accomplished via the foot switch box  62  as described above. The foot switch box  62  operates in a fashion similar to the manual switch interface  60 . Use of the foot switch box  62  would allow a musician to cause the guitar  12  to obtain an alternative tuning while leaving the musician&#39;s hands free for other activities.