Abstract: Clavier multiplexing is used in the present keyboard musical instrument to reduce the number of sound generators needed by connecting them only to those notes that are depressed. The association of a tone generator with a control unit, which provides the tone generator with frequency, force, and speed information, continues as long as possible, and even after the associated note is released and until the control unit is needed to attend another note by use of independent address and idle-busy storage registers. The note address is digitally designated and remembered, sequential start up logic is used for a control unit. In the glissando mode, the address of the note of the pair involved in the glissando that was released last must be remembered, and the voltage-controlled oscillator involved must have continuing access to this address.

Abstract: A hand-held electronic musical instrument and system has a plurality of resistance elements that have adjacent thereto indentations or notches, or other tactile structures for locating discrete notes. Each resistance element is connected to a circuit for translating the position of the musician's finger on the element into an electrical signal, the frequency of the signal corresponding to the position touched. Transducers convert the electrical signals into sounds, which are modified by an acoustic cavity within the instrument. At least one control panel is provided on a side of the instrument engaged by the thumb or thumbs of the musician, each control panel also being a one-dimensional touch panel with the control axis perpendicular to the long axis of the panel so that the musician's thumb can slide along the panel parallel to the long axis without changing its position in the control axis. The musician controls the volume of the sound by adjusting the position of the thumb transverse to the instrument.

Abstract: A musical instrument is disclosed in which light beams striking a detector produce various tones and the loudness of the sounds produced is dependent upon the intensity of the light beam which can be changed by interrupting the beam or reflecting the light backwards to a detector situated next to the light source. A special amplifier circuit is provided which responds to both the amount of light beam interruption as well as the rapidity of interruption. The invention can be variously embodied in woodwind, string and percussion instruments and can also be used on a stage and controlled by moving dancers or musicians.

Abstract: A keyboard for a musical instrument having a frame structure and a plurality of elongated keys. Flat pivot springs are provided for each key and are rigidly held in a vertical position in the frame structure. Each key has a chamber with a lower opening in a rear section for receiving the upper section of an associated pivot spring so that the pivot spring forms the sole pivot about which the key may rotate in a single plane only. The pivot spring is rigidly held in the key chamber in a force fit without the use of a separate fastening device.

Abstract: First to third switch contact pairs are provided for each of the performance keys of an electronic keyboard musical instrument such that they are successively closed in an interlocked relation to the operation of the associated key. A first time interval from the closure of the first switch contact pair till the closure of the second switch contact pair and a second time interval from the closure of the second switch contact pair till the closure of the third switch contact pair are counted in a CPU, and their ratio is obtained therein. The tone color of the output musical signal is controlled according to the value of this ratio, and the volume of the musical signal is controlled according to the length of the second time interval.

Abstract: A musical toy comprising a tone generator, a plurality of spaced apart generator contacts respectively associated with differing musical tones of a musical scale; at least one set of contactor members; at least one set of receiver members uniquely adapted to receive the set of contactor members in a fixed predetermined relative position; displacing members for displacing said receiver members while maintaining said fixed relative disposition in juxtaposition to the contacts so that they are successively actuated by the receiver members in accordance with a predetermined sequence thereby generating a predetermined sequence of tones.

Abstract: A key device, as used in a keyboard, comprises(a) a hinge,(b) a key tab projecting in one direction relative to the hinge, and connected with the hinge,(c) a pusher projecting in another direction relative to the hinge, and connected with the hinge, and(d) a spring arranged to be deflected when the key tab is downwardly depressed about the hinge axis, to resist such depression.

Abstract: A data entry device durable enough to withstand the rigors of industrial type usage in which the electronic components are isolated from the external environment is described. The device comprises a molded elastomer keyboard matrix with thin stainless steel keypads. Embedded into the elastomer beneath the keys are small magnets. Solid state Hall-effect switches are mounted at a predetermined distance from the magnets and are separated from them by a magnetically permeable stainless steel sheet which forms part of the enclosure isolating the electronic components from the environment. Depressing one of the keys on the elastomer matrix moves its associated magnet toward the respective Hall-effect device, causing a change in current which may be sensed by other electronic components. Because of the elastomer material, the keys spring back when released.

Abstract: An organ key assembly having a loosely mounted switch actuator providing self-aligning movement of the actuator relative to the switch. The switch, in the illustrated embodiment, is a membrane switch. The actuator is arranged to slide across the switch in effecting the operation thereof. The actuator is associated with the key in such a manner as to permit the key to be moved from an undepressed, normal position to the fully depressed position, with a substantially constant force. The actuator defines a novel configuration for providing the self-aligning function and switch wiping operation. In the illustrated embodiment, the switch is provided as a portion of a printed circuit board. A support structure is provided for preventing deformation of the printed circuit board by the actuator biasing forces.

Abstract: A musical synthesizer keyboard has a plurality of keys mounted so that each key may be displaced along and return along a locus of movement and where during travel in either direction along said locus a key causes a change of state in each of two corresponding optical detectors at spaced locations along said locus. Means are provided for signalling the states of the detectors to other equipment.

Abstract: This is an electrical switch mechanism actuated by a piano-style key of a musical instrument. The switch consists of a pair of cross-bar contacts, at least one of which is resiliently flexible. This resilience permits a moveable contact member to be driven into engagement with a fixed contact member, and also keeps it firmly biased against the fixed contact member for electrical communication therewith whenever the key is in its actuated position. When the key is released, an actuator member on the key captures the moveable contact and moves it away from the fixed contact. Upon actuation, the key over-travels beyond the point of contact engagement, but the actuator decouples from the contact so as to avoid any increase in contact pressure and prevent double-keying. Various techniques for minimizing impact noise during contact recapture, and for mounting the contacts upon a circuit board, are also disclosed.

Abstract: An electronic musical instrument of simple arrangement wherein a plurality of musical tones of different musical instrument types are preset; musical tones of a desired musical instrument type is first selected; musical tones belonging to the selected one of the plural musical instrument types are played by performance keys; the performance keys are concurrently used for selection of musical tones of the desired musical instrument type, and which comprises a changeover switch for determining the application of the performance keys for the original purpose or for selection of a desired musical instrument type, thereby eliminating the necessity of providing separate musical instrument type-selecting key or keys in addition to the performance keys.

Abstract: A keyboard operated musical instrument with portamento effect in which the portamento keyboard consists of a linear array of keyswitches. The keyswitches are arranged in groups corresponding to each musical note and spaced so that a number of contiguous switches are actuated by each finger in contact with the portamento keyboard. Apparatus is provided for generating a frequency number corresponding to the closest switch actuated by the center of each finger thereby providing polyphonic portamento effects as the finger positions are slid or changed along the portamento keyboard. The frequency numbers are utilized to control the pitches of tones generated by the musical instrument.

Abstract: An electronic musical instrument comprises a power source switch, a keyboard including a plurality of key switches corresponding to a plurality of keys, a signal generator for generating a musical tone signal corresponding to a note of a depressed key, and a loudspeaker driven by an output of the signal generator for producing a musical tone. In the instrument, the power source switch is interlocked with the key depression operation so as to supply power to the electronic musical instrument only when a key is depressed.

Abstract: A pressure responsive, variable resistance, analog switch has first and second conductors interleaved in spaced-apart relationship and disposed on a base member. An insulative spacer ring is positioned around and rises above the first and second conductors. A resilient cover sheet is attached to the top of the insulative spacer ring in spaced relationship over the conductors to define an enclosure between the resilient cover sheet and the base member. A pressure sensitive resistive conductor composition is disposed on the resilient cover sheet or on the conductors in the enclosure to interconnect a resistance between the first and second conductors when the resilient cover sheet is depressed against the conductors. The amount of resistance so interconnected varies inversely to the amount of pressure exerted.

Abstract: A pressure responsive, variable resistance, analog switch has first and second conductors interleaved in spaced-apart relationship and disposed on a base member. An insulative spacer ring is positioned around and rises above the first and second conductors. A resilient cover sheet is attached to the top of the insulative spacer ring in spaced relationship over the conductors to define an enclosure between the resilient cover sheet and the base member. A pressure sensitive resistive conductor composition is disposed on the resilient cover sheet or on the conductors in the enclosure to interconnect a resistance between the first and second conductors when the resilient cover sheet is depressed against the conductors. The amount of resistance so interconnected varies inversely to the amount of pressure exerted.

Abstract: A potentiometer comprises a support member having first and second support regions and an intermediate region located therebetween, a resistive member supported on the support member at the first support region thereof and having a longitudinal dimension extending transversely of a line from the first support region to the second support region, and a resilient contact member secured to the support member at the second support region and extending over the intermediate region and terminating superjacent the resistive member.

Abstract: Device for the manual playing of electronic musical instruments. Each manual has three groups of keys respectively arranged along three tilting bars, for operation by three fingers on one hand of the player. When a key is pressed at one end, it tilts the bar on which it is mounted in one direction, and one tone is produced. If the same key is pressed at the opposite end, it tilts the bar in the opposite direction, and a different tone is produced. Special control keys or action converters include a roll positioned so that it may be operated by the thumb of the same hand which is playing the keys. Rotation of the roll by the thumb produces one control signal affecting the sound issuing from the instrument, and axial motion of the roll by the thumb produces a different control signal. Other refinements and improvements are disclosed.

Abstract: A dual switch apparatus has two switches simultaneously actuated in response to a single touch force where at least one of the switches has a pressure responsive variable contact resistance. A first support member has a first and a second conductor disposed thereon and a second support member has a third and a fourth conductor disposed thereon so that the first and third conductors and the second and fourth conductors have mirror image conductor patterns. A semiconducting composition layer is disposed to cover at least one of the four conductors. The first and second support members are positioned facing one another with the first and third conductors and the second and fourth conductors transversely aligned so that a transverse force causes the first and third conductors and the second and fourth conductors to move into electrically conducting relationship. A spacer maintains the first and second support members in normally spaced relationship.

Abstract: A multiple touch switch apparatus has at least one multiple segment conductor ply on the top surface of a support ply. The segments are electrically insulated from each other by their lateral displacement but are immediately adjacent so that a selected one or more of the segments can be contacted in response to a single transverse touch force. A second support ply has a unitary conduction ply on its bottom surface spaced apart from, but facing, the multiple segment conductor ply. At least the second support ply and the unitary conduction ply are resilient deformable into contact with one or more segments of the multiple segment conductor ply. Each of the multiple segment conductors or the unitary conduction ply or both may incorporate a conductor layer and a pressure sensitive semiconductor composition layer disposed thereon. The semiconductor layer provides a pressure sensitive variable contact resistance in series with the switch.

Abstract: A piano action keyboard for an electronic musical instrument or the like wipes a switch actuator (or other mechanical component of electric signal translation means) across switch contacts on a printed circuit board to generate signals indicative of the position and motionof a key when played. The keyboard provides a highly realistic piano "feel" through an array of paired depressable playing keys and arms. Each such arm supports a switch actuator or the like, with varying force transmission at different stages of depression of its corresponding key, the overall electrical-mechanical combination affording a response in terms of both actual results and kinesthetic feedback simulating a manual piano action.

Abstract: A keyboard assembly for electronic musical instruments such as electronic pianos is constructed from a key switch unit and a resilient holder block for mounting the key switch unit to a key frame via simple snap coupling. The key switch unit includes a resiliently deformable movable contact common to all keys in combination with given printed circuits including a plurality of fixed contacts so that, when any key is depressed, the movable contact is locally depressed by an actuator accompanying the key and brought into provisional contact with a corresponding fixed contact in order to selectively switch on a corresponding printed circuit for generation of a musical tone.

Abstract: A multi-function touch switch apparatus has a first semiconductor composition layer disposed on top of a first conductor layer which is affixed to a first base member. A second semiconductor composition layer opposing the first semiconductor in spaced relationship thereto is disposed on a second conductor layer which is itself disposed on the bottom surface of a second support member. A third conductor layer is also disposed on the top surface of the second support member in opposing spaced-apart relationship to a fourth conductor layer disposed on the bottom surface of a third support member. The second and third support members and the affixed conductor layers and semiconductor layers are resiliently deformable in a transverse axis in response to a transverse touch force to thereby cause electrical contact between the second and third conductor layers to provide a closed switch and the first and second semiconductor layers to provide a closed switch in series with a pressure sensitive resistance.

Abstract: An I.sup.2 L circuit for superimposing audio-frequency electrical signals in an electronic organ is provided. With each current unit of audio-frequency to be superimposed a double-collector I.sup.2 L transistor is associated, and each key is coordinated to an injector, the current of which is switched by said key. In addition to the collecting bars into which said current units are fed, there is provided a separate collecting bar into which the non-audio-frequency collector currents of double collector transistors are fed, each of which being coordinated to each injector. A bounce effect is avoided by subtracting the signal of the separate collecting bar from the signals on the other collecting bars.

Abstract: An electronic musical instrument incorporates one or more pressure sensitive push-button controllers actuable independent of the keys or other note selecting elements of the instrument to vary a corresponding number of musical parameters. The specific controllers provide a sensitive, smooth, repeatable parameter variation in response to both the location and the force of the player's touch.

Abstract: An electronic musical instrument which has any desired compass of musical sounds and which produces justly intoned pitches based on any desired pitch or note and which is capable of changing at will during performance the basic pitch or the "do" (of do, re, me, etc.). The instrument has a single master oscillator having means for changing the pulse interval at will and during performance. The output of the oscillator is fed to a system of counters and gates, the output of which is a number of pulse trains which are related in frequency by ratios of small integers and which ratios are maintained unchanged regardless of the frequencies of the various outputs. The instrument includes a keycylinderin place of the usual keyboard and it has on its surface several helices of conductive contacts.

Abstract: An apertured insulating strip permits closing a circuit only at contact points defined by the apertures between a low resistance conductor and a high resistance conductor in an electronic circuit of the type which produces musical notes each having a frequency dependent upon the resistance downstream of a particular contact point.

Abstract: This invention concerns a monolithical integrated organ gate circuit showing a load resistance common to all audio signal currents. For the suppression of any bounces possibly occurring upon the operation of a second key after a first one, there is a rest current coordinated to each audio signal current which rest current is fed to the load resistance when the related key is not operated and which rest current amounts to the mean value of the related audio signal current.

Abstract: A piano-action keyboard for an electronic musical instrument or the like wipes a switch actuator (or other mechanical component of electric signal translation means) across switch contacts on a printed circuit board to generate signals indicative of the position and motion of a key when played. The keyboard provides a highly realistic piano "feel" through an array of paired depressable playing keys and arms. Each such arm supports a switch actuator or the like, with varying force transmission at different stages of depression of its corresponding key, the overall electrical-mechanical combination affording a response in terms of both actual results and kinesthetic feedback simulating a manual piano action.

Abstract: A keyboard for a monophonic musical instrument has a plurality of touch sensitive keys which function as variable capacitors, the capacitance depending on the force applied to the keys. The variable capacitance is detected and used to produce a variable control voltage which is used to execute one or several of various control functions, such as controlling the volume of the sound produced by The instrument, controlling the cutoff frequency of a low pass filter in the output system of the instrument, controlling the amount of vibrato or other periodic modulation introduced into the sounds produced by the instrument, controlling the frequency of the vibrato or other periodic modulation, or controlling the amount of "bend" in the pitch of a sound produced by the instrument, i.e. shifting the pitch slightly from its nominal value. The variable capacitors employ a conductive elastomer which is deformed in response to the force applied to the keys.

Abstract: A keyboard assembly includes a U-shaped carrier member and a plurality of key members connected thereon by resiliently yieldable legs having detent portions which engage cooperating recesses provided in the bottom wall of the U-shaped carrier member with snap action. Each key member has an upper and a lower housing port which are snap-fastened to each other, and an actuating shaft axially movable to energize an electrical component mounted below the carrier member. A locking member is also provided to lock the shaft in a down actuating position.

Abstract: The present invention is an electronic musical instrument the type in which information of the actuation of keys is detected by scanning the keys of a keyboard. The electronic musical instrument includes keys selectively actuable for producing sounds which correspond to respective musical scale notes, circuitry for sequentially scanning these keys for detection of the information of the actuation of these keys, and a memory circuit corresponding to each of the keys so that the information of the actuation of the keys is stored in the memory circuits.

Abstract: An acoustic signal generator circuit produces electrical acoustic signals ose frequency spectrum and envelop curve respectively determine the acoustic parameters, pitch and timbre and, respectively, the change in amplitude with time and accordingly the volume, attack and decay phenomena and also quasi stationary behavior of the corresponding sound. There is a manually actuated control device for influencing at least one part of the acoustic parameters. The control device can be constructed in a manner similar to an accordion with a blow bellows and at least one keyboard.

Abstract: A keyboard device for an electronic musical instrument made according to the applicant's invention comprises a printed circuit board formed with pairs of stationary contacts corresponding to respective keys and a common movable contact member made of elastic rubber and disposed over the circuit board for connecting each pair stationary contacts. The common movable contact member is used for plural pairs of stationary contacts and on-off condition of each key switch is detected in time division. The movable contact member is simply placed in position on the printed substrate and holding members are provided on a keyboard frame for restricting lateral expansion of the movable contact member which takes place when the movable contact member is brought into contact with the stationary contacts by depression of the keys.

Abstract: Disclosed is an electronic musical instrument resembling a guitar that is played like a guitar and sounds like a guitar; however, it is stringless and has a plurality of flexible actuator blade type members which are mounted on edge and are adapted to be strummed or picked. Flexing of each actuator blade in either direction closes one or more leaf type switches which controls the amplified output of an electronic oscillator whose fundamental operating frequency is further varied in accordance with finger actuation of a plurality of fret-board switches. Although the invention in its preferred embodiment is directed to a guitar-like instrument, it is also applicable to other types and classes of musical string instruments such as a violin.

Abstract: Disclosed is a touch operated capacitance switch which may be used in connection with a digital arpeggio system for an electronic organ that through the use of digital techniques permits arpeggios, note sequences as well as strum, multi, organ, and normal modes of operation to be played automatically. Two counters scan by counting through an 8.times.8 matrix of 64 words covering the 61 notes of an organ in rapid sequence upon the playing of one or more organ keys. Each word is fed to a corresponding one of 61 decoders, one for each note of the keyboard. If a corresponding key has been played, the decoder provides a signal to a corresponding pulser circuit which enables a corresponding keyer to transmit an audio signal from an audio oscillator corresponding to the played key to an output system and loudspeaker.

Abstract: An electromagnetic pickup device for use in a tone generator of an electronic piano includes a plurality of vibratory reeds and pole pieces of pickups which are so shaped that each reed and pole piece are opposed to each other in a range from the neutral position of the reed to a position within its maximum vibrating amplitude at one side. In output signals of the pickups, the balance of fundamental and odd- and even-numbered harmonics is improved to generate a tone which is close to that of a normal string piano.

Abstract: An improved switch mechanism for controlling the actuation of a plurality of electrical switches by means of tablets of a musical instrument, such as an organ. The mechanism permits a plurality of tablets to be depressed simultaneously and releasably retained in the depressed position so as to maintain a selected actuation of switches such as for providing selected voicing circuits in an organ. The mechanism is arranged to cause an automatic release of any previously depressed tablet as an incident of the user depressing subsequently one or more tablets to the switch actuating position. The tablets may be biased to the switch releasing position with the mechanism permitting the biasing structure to return the tablets to the switch releasing position as an incident of such further tablet depression.

Abstract: A switch mechanism designed to overcome the problem of electrical noise employs a compound movable contact assembly, including a coil spring member and a smooth-surfaced wire contact member mounted thereon. The flexing of the coil spring provides an advantageous rolling, wiping motion for the wire contact member, without the noise-producing electrical discontinuities associated with earlier mechanisms in which the coil spring itself made direct electrical contact.

Abstract: A touch responsive unit for a keyboard electronic musical instrument. A high frequency signal source is connected to one plate of a normally open circuited variable capacitor. The other plate of the variable capacitor being mechanically connected to a force transferring mechanism and electrically connected to a circuit means for generating a control voltage envelope. The depressive force applied to the key through the transfer mechanism causes the capacitor plates to overlap. The degree of area overlap is proportional to the depressive force and determines the capacitance value. As the plate area overlap increases, the capacitance value increases and the peak amplitude of the high frequency source passed by the capacitor increases. The control voltage envelope of the circuit means is applied to a standard keyer circuit to amplitude modulate a tone signal source corresponding to the selected key. The slope or decay rate of the control voltage envelope is regulated by the circuit means.

Abstract: An envelope waveform generating apparatus comprising a key code generating device composed of a means for releasing key code data and a means for outputting first and second control signals, a key assignor composed of a means for outputting a third control signal, a level setting means, and a function generator. The envelope waveform generating circuit is provided with a touch response so that the level of envelope waveform may readily be set.

Abstract: A sophisticated polyphonic instrument providing both additive and subtractive tone synthesis capabilities for generating a myriad of timbres, yet occupying a volume comparable to a toy accordion, is described. The unusually broad capabilities, for a small size synthesizer, is achieved through use of the novel LSI oriented circuits described in copending applications entitled "Electronic Organ With Multi-Pitch Note Generators", Ser. No. 610,733, filed Sept. 5, 1975, and "Automatic Arpeggio For Multiplexed Keyboard", Ser. No. 675,834, filed Apr. 12, 1976. The small size is made possible by use of LSI circuits in conjunction with a novel note keyboard arranged to select any note of the chromatic scale over a five octave range with only five keys, played by the right hand, and a novel chord keyboard, played by the left hand, arranged to select any one of ten chords based on the selected note as its root. The chord may be selected in its fundamental or either of two inverted forms.

Abstract: The hand-held instrument is preferably supported by a strap from the neck for one or two handed playing of a keyboard with switch and potentiometer controls of a remote synthesizer which may be basically of conventional design and include a plurality of output voice means. A lightweight keyboard assembly is mounted within an elongated premolded housing having a control panel comprised of control switches and light indicators. The instrument is preferably for playing by the right hand, and for the purpose of holding and controlling the stability of the instrument, the housing is formed with a left hand gripping hole or slot permitting the instrument to be firmly gripped. Adjacent the hole there are provided additional control knobs and push button switches which are easily operated by the left hand without any repositioning of the hand. An umbilical cord interconnects the hand supported keyboard musical instrument and the synthesizer apparatus.

Abstract: A keyboard assembly includes a U-shaped carrier member and a plurality of key members connected thereon by resiliently yieldable legs having detent portions which engage cooperating recesses provided in the bottom wall of the U-shaped carrier member with snap action. Each key member has an upper and a lower housing port which are snap-fastened to each other, and an actuating shaft axially movable to energize an electrical component mounted below the carrier member. A locking member is also provided to lock the shaft in a down actuating position.

Abstract: A keyboard operated polyphonic tone synthesizer which is touch responsive to the force applied to the keyboard mechanism. Operation of a key operates through a pneumatic transducer to provide an air stream having a velocity proportional to the force applied to the key. A transducer responsive to the velocity of the gas produces an output pulse having a peak amplitude proportional to the peak velocity of the air. This voltage in turn is used to control the peak amplitude of a musical tone generated in response to the operation of the key so that a direct relation exists between the force with which the key is operated and the amplitude of the resulting sound generated by the instrument.

Abstract: A step-on type tone scale play device has a flexible mat within which is arranged a plurality of flexible switch elements in accordance with a tone scale and is adapted to produce corresponding music sounds when marks configured on the surface of a mat to indicate the position of each switch element are stepped on.The device is very easy to keep and carry, and convenient to display or perform as compared to the conventional device, as the mat is light and capable of folding or rolling into a compact form.

Abstract: This invention relates to a touch response sensor for an electronic musical instrument capable of producing a signal responsive to a key depressing speed upon depression of a key. In order to produce such a signal from the sensor, the latter comprises two switches which are operated in turn by a single drive piece with a time lag determined by the key depressing speed. The secondarily operated switch may be a switch capable of producing a signal responsive to a key depressing pressure and including a resistant member and a resilient member having a conductive portion facing the resistant member thereby, upon depression of the resilient member through the key, to produce a resistance variation signal responsive to the key depressing pressure.

Abstract: The disclosure describes an improved digital oscillator for use in an electronic musical system capable of converting electrical tone signals into corresponding sound waves. The oscillator includes an adder, accumulator and multiplexer for selectively transmitting either a divisor number or increment number to the adder. The oscillator cyclically performs incrementing operations by using the increment number over a variable range established by the divisor number at the beginning of each cycle. When the modulus of the adder is exceeded, the adder generates a carry pulse and a remainder. The divisor is then added to the remainder before the incrementing operations begin again. A digital calculator automatically calculates the proper values of the increment and divisor numbers so that the carry pulses occur at a predetermined frequency.

Abstract: An electronic musical instrument has a keyboard equipped with apparatus for developing a voltage in response to the momentum of operated keys of the keyboard, which voltage is employed to control the amplitude of the sounds produced in response to each key depression. The amplitude is dependent partially upon the momentum of the key depression and partially upon the amount of time since the previous depression of the same key. An envelope generator operates in response to depression of a key and has a charge circuit for controlling attack and decay of the envelope. The discharge circuit is controlled partially by the pitch of the note selected by the depression of any given key of the keyboard. The envelope produced by the envelope generator controls a unit which functions as a combined modulator and filter, closing a path between an audio source and an output system and varying the width of the band-pass provided for the signal from the audio source in response to the amplitude of the envelope.

Abstract: Disclosed is an electronic musical instrument resembling a guitar that is played like a guitar and sounds like a guitar; however, it is stringless and has a plurality of flexible actuator blade type members which are mounted on edge and are adapted to be strummed or picked. Flexing of each actuator blade in either direction closes one or more leaf type switches which controls the amplified output of an electronic oscillator whose fundamental operating frequency is further varied in accordance with finger actuation of a plurality of fret-board switches. Although the invention in its preferred embodiment is directed to a guitar-like instrument, it is also applicable to other types and classes of musical string instruments such as a violin.