Abstract: A solenoid driving apparatus for actuating keys of a player piano is provided in which respective key striking strength data can be applied to respective solenoids of keys, so that musical tones can be reproduced correctly and in which the key striking strength data at the time of musical performance can be compensated for high fidelity reproduction. The solenoid driving apparatus includes a plurality of keys and solenoids provided on each key. When a key is depressed, a first key striking strength data corresponding to key striking strength and a data designating the depressed key are generated. The first key striking strength data is then converted into a second key striking strength data so as to make the latter data in linear proportion to an operating or response speed of the solenoid. In accordance with the second key striking strength data, a solenoid driving data is generated, and is applied to the solenoid corresponding to the key designated by the designating data.

Abstract: The present invention is an electronic piano that includes various "easy play" features that enable a person with little musical training to play the piano producing music similar to that of a skilled musician. The "easy play" feature automatically creates musical and rhythmic piano accompaniment patterns in response to playing either one key (One Finger Chord mode) or a chord (Funchords mode) with the left hand. The player plays the melody of the desired tune with the right hand. Instead of having to move the fingers of the left hand to play complex piano accompaniment patterns, as with a conventional piano, the player only needs to play a note or chord, and move the finger or fingers of the left hand to a different playing key or keys to change chords and patterns. In the standard piano mode, this instrument resembles an acoustic piano in function. The invention also includes a set of pushbutton switches which control the "easy play" features of the instrument.

Abstract: An envelope wave shape for each musical tone wave shape is generated per each key operation. The rate of change of the envelope wave shape to be generated are switched at timings corresponding to key operation speed of an operated key, thereby enabling an electronic musical instrument to generate musical tones of different envelope patterns depending on key operation speed just like on a pipe organ.

Abstract: A key-speed-responsive volume control apparatus for a keyboard-type electronic musical instrument includes a key switch associated with a key of the instrument, wherein a movable contact of the key switch moves out of engagement with a break contact and into engagement with a make contact upon depression of the key. A capacitor is charged following the movement of the movable contact out of engagement with the break contact and before engagement with the make contact. The capacitor is made to discharge at a first prescribed rate immediately after charging until the movable contact comes into engagement with the make contact, and then at a second prescribed rate until the movable contact disengages the make contact upon release of the key.

Abstract: An electronic percussion synthesizer is disclosed which includes a plurality of pressure transducers, each representing a different percussive musical instrument. Each transducer is responsive to an external striking force for generating analog pulses, each pulse representing one beat of the respective musical instrument. The transducers are mounted to a synthesizer housing in a manner which mechanically isolates the transducers from each other. Sound signal generating circuits are provided which are responsive to the analog pulses for generating sound signals comprising the beat of the respective musical instrument. The amplitude of the signal representing each beat is proportional to the magnitude of the force used to generate the respective analog pulse. The synthesizer also includes storage and playback circuitry for digitally storing a series of pulses, each pulse representing a percussive beat; for playing back the stored pulses; and for storing additional pulses in an interleaving manner.

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 touch responsive keyboard musical instrument is provided with an array of keyboard switches arranged in octave groups and connected in parallel octaves. A motion transducer is attached to each keyswitch so that a transducer signal is generated corresponding to the motion used to actuate the keyswitches. The keyswitches are sequentially scanned until an actuated keyswitch is detected. At this time the scanning is interrupted until the corresponding transducer signal has reached its peak value. The peak value is used to vary a tonal effect such as a frequency modulation or an ADSR envelope modulation of a tone generator assigned to the actuated keyswitch. The keyswitch scanning is resumed when the peak value of the transducer signal has been measured.

Abstract: An electronic piano includes a tone generator having a pulse generator and a discrete TOS circuit for each octave. The input of the first TOS circuit is connected with the pulse generator and the input of each next-following TOS circuit is connected with the input of the preceding TOS circuit by a divide-by-two divider circuit. The outputs of each TOS circuit are connected with discrete control circuits each having an analog switch for each output of the respective TOS circuit. First inputs of the analog switches receive envelope control voltage signals on depression of the respective piano keys while second inputs of the analog switches receive tone signals from the corresponding outputs of the respective TOS circuits. The outputs of the analog switches transmit tone signals, which are modulated as a function of the intensity the corresponding envelope control voltage signals, to a loudspeaker by way of either one of two main branches of the respective control circuits.

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: A player piano recording system has photosensor flags secured to the undersides of the piano keys, vertical movement of which is detected by horizontally adjustable photosensors to produce "key played" and key velocity signals which supplied to a microprocessor for deriving expression signals for recording on magnetic tape. The microprocessor provides output expression values and key play information. According to the invention, the expression values are a direct function of key velocity and key play information and switch selected boost (an enhanced initial frame expression for overcoming solenoid inertia) and add (for trill) values. Key play data is dependent upon key play inputs and the frame extension switch value. The unique structure of the key flag permits horizontal adjustment of the photosensors for vertical misalignments etc. of the piano keys.

Abstract: An electronic musical instrument wherein depression of a key entails the discharge of a primary capacitor which is connected to the inverting input of an operational amplifier whose output is connected with a second capacitor serving to supply envelope control voltage signals to an analog switch which connects a tone signal generator with a tone processing unit. The extent to which the primary capacitor discharges depends on the speed of movement of the key from non-depressed to depressed position, and the intensity of residual voltage of the partially discharged primary capacitor determines the intensity of the envelope control voltage signal. The speed at which the second capacitor discharges can be regulated to produce sustain or banjo effects. The second capacitor is in series with a resistor in a feedback conduit connecting the output and the input of the operational amplifier.

Abstract: An action is described for musical instruments of the piano type. Means are included for braking and restraining each hammer of the action to prevent bouncing, rebounding, or other undesired movement, when the key is depressed and the hammer is positioned at the escapement distance from the tone generating tine and also when the key is released and the hammer is at rest position. The braking and restraining means move arcuately in cooperation with the key to exert a wedging force against a portion of the head of the hammer to brake and restrain it in the desired positions.

Abstract: A tone generation system is intended for use with an electronic musical instrument of the type wherein an audible tone is generated electronically in response to actuation of the instrument by a player. The invention generates digital signals capable of defining either the waveshape or the envelope or characteristic of a tone for each tone initiated by such player actuation the latter envelope being varied in accordance with the intensity of the player actuation initiating that tone. In the latter case, digital electronic circuits are utilized for developing a digital scaling signal S corresponding to the intensity of actuation of the instrument by the player, and a digital envelope signal which represents slopes and Y intercepts of portions of a composite waveform, viewed in an orthogonal coordinate system. These digital circuits arithmetically manipulate these scaling signals and envelope signals to give a composite output signal defining the envelope.This application is a continuation of application Ser.

Abstract: An electronic musical instrument generates musical tone signals by digitally executing the calculations of equations representing frequency modulation. The instrument comprises a keyboard information generating circuit for generating key information concerning depressed key numbers and key touch information concerning key operation, a plurality of system parameter generating circuits for providing parameter information in response to the outputs of a tone color selecting switch section, a plurality of system musical tone signal forming sections each for producing musical tone signals through the digital calculation of the FM equation in accordance with the abovementioned informations, and a musical tone generating section for producing musical tones by combining the musical tone signals provided by the musical tone signal forming sections, the musical tone signal forming sections calculating the FM equation by using different parameters provided by the parameter generating circuits.

Abstract: A touch responsive tonal envelope waveshape control system is provided for an electronic musical instrument which includes cooperating tone generating and keying circuits which are responsive to actuation of a key for initiating the generation and keying of a corresponding tone. The system of the invention includes encoding circuits responsive to the actuation of a key for producing encoded signals corresponding to the intensity of player actuation of the key and an amplitude control circuit responsive to these encoded intensity signals and cooperative with the keying circuits for controlling the peak amplitude of the tonal envelope waveshape in accordance with the intensity of player actuation of the key for initiating that tone.

Abstract: A timbre-select type electronic musical instrument in which the application of a sound effect unsuitable for the selected timbre is automatically blocked. This instrument includes means for detecting that a certain timbre is selected and means responsive to the signal from said detecting means for preventing the unsuitable effect for the timbre from being applied to a sound.

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: An electronic musical instrument using continuous tone generators capable of simulating the sounds of a conventional acoustical piano. The instrument includes a gating circuit featuring a timed switch travel circuit having a double-time constant for improved control of the dynamic range from the keyboard, and a soft pedal controlling the keying voltage to produce more realistic emulation of the dynamic effects of an acoustical piano. The gating circuit produces a double-time-constant envelope of nearly harmonically related signals for a more realistic piano timbre. The tone spectrum is also controlled as a function of signal level by means of a resistor matrix feeding selected inputs of an active ladder filter, in order to reproduce timbre variation with dynamic level.

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: Pedal control circuits for use with an electronic musical instrument, such as a piano, which provide control functions analogous to the actions of a sustaining pedal, of a sostenuto pedal, and of a volume pedal of a conventional piano. Damper circuits operable in conjunction with a sustaining pedal provide an effect analogous to the action of the sustaining pedal in a conventional piano, a latching circuit actuated by depression of a sostenuto pedal operates in conjunction with the damper circuits in a manner analogous to the action of a sostenuto pedal in a conventional piano, and a volume pedal and associated circuitry is operative to determine the level of the output tones only at the moment of strike of the keys, an action analogous to that of the volume pedal in a conventional piano.

Abstract: A circuit for generating a percussion envelope for use in electronic organs and similar electronic keyboard instruments wherein the envelope has an attack overshoot, a long decay, and a snub decay when the key is released. A velocity sensing feature is included, whereby the force with which the key is struck determines the amount of capacitor discharge, and the voltage remaining on the capacitor is compared with the amplitude of the attack portion of the envelope such that decay is initiated when a compare condition is reached. A second comparator sets the amplitude at which the envelope undergoes transition from a fast decay to the normal long decay. The timing for the attack and three decay portions of the envelope are independently controlled by means of four clock driven electronic gate circuits which incrementally charge and discharge the main timing capacitor. The gate circuits include a pair of serially connected field effect transistors having a capacitor connected at their juncture.

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: There is disclosed a system for encoding of bass and treble expression effects while recording from the keyboard of an electronic player piano wherein the intensity of the music being recorded is reflected in variations in the power of the acoustic waveform produced thereby. The key note or key switch actuations are multiplexed in a serial bit stream of data and stored in a shift register and then separately combined with the bass and treble expression data bits in a format which, upon re-creation of the original musical presentation, results in a more faithful rendition of the original performance.

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: There is disclosed an expression system for playback of a magnetic tape record rendition of a musical presentation. The detected intensity level for the bass and treble halves of the keyboard are assigned different data bit positions in the frames of recorded data bits of a time division multiplexed record system. The binary bits are weighted and used to modulate the width of pulses supplied to selected solenoids which actuate the striker-hammer members of the instrument so that the average drive energy applied to the solenoid is proportional to the desired intensity thereby more faithfully reproducing the manual action of the original performer.

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 frequency generator for a keyboard operated electronic music instrument using a single master clock source for selectively producing all the notes of the musical scale. A set of frequency numbers corresponding to each of the notes of a diatonic scale are stored in a memory. A frequency number is selected from the stored numbers according to the note to be generated when a key on a keyboard is activated, the selected number being applied to an adder-accumulator periodically at the master clock rate for incrementing the contents of the accumulator. Overflow pulses from the adder-accumulator shift amplitude values sequentially from a set of values stored in a shift register through an adder to a digital-to-analog converter. The adder modifies the amplitude values by applying a fractional part of the incremental difference between each value and the next value in the sequence to the adder. The fractional amount is determined by the content of the adder-accumulator and changes with each master clock pulse.

Abstract: A device for encoding the expression of a keyboard percussive instrument is disclosed. The apparatus places a suitable AC voltage on a coating applied to a hammer and positions a pair of capacitive coupled pads near the string to be struck by the hammer. As the hammer sweeps past the pads, signals are capacitively coupled from the hammer motion to the pads. Suitable latches are set and unset to form a signal which is coupled through a switch, a sample and hold amplifier, then to an analog to digital convertor which forms an expressive signal of N bits length. The signal is begun by depression of the key and is terminated by closure of the key upon release by the musician, the key of the instrument being provided with capacitive pickup pads coupled to the key and through a reset gate to the latches. Alternate embodiments are additionally disclosed.

Abstract: This invention relates to a touch response sensor for an electronic musical instrument which may control the volume, pitch, tone-color or the like of the musical tones produced by the instrument upon depression of the key responsive to the key depressing pressure. In order to detect the key depressing pressure, the touch response sensor has an electrically conductive resilient member having two legs downwardly extending therefrom for producing resistance variations between contact pieces provided on a base plate under the resilient member in response to the key depressing pressure. The contact pieces are, for example, connected via lines to a voltage-controlled variable-frequency oscillator circuit, voltage-controlled variable filter circuit, voltage-controlled variable gain amplifier circuit or the like so as to vary the volume and the like of the tones in accordance with the key depressing pressure.

Abstract: A tone-generating system for an electronic musical instrument of the percussion type is provided wherein an audible tone closely approximating the corresponding tone of a conventional instrument is generated electronically. A single-pole, double-throw switch is actuated by a key to initiate generation of the tone and a tri-level detecting circuit coupled to the switch is utilized to determine which of the three states the switch is in; that is, the two "throws" or positions of the switch which correspond to the released and depressed positions of the key, and the state in which the switch is between the other two positions. By detecting the three states and developing corresponding control signals, counting circuitry may be utilized to determine the intensity with which the key is depressed to enable generation by a read-only memory of digital scaling signals representative of the variations in amplitude of the initiated tone with respect to the intensity with which the key is depressed.

Abstract: A touch sensitive device is associated with at least one key of an electronic musical instrument such as an electronic organ, includes a layer of a pressure responsive, variable conductance material, and exhibits a switching action when subjected to pressure beyond a threshold pressure, any increase in pressure thereafter providing an increase in conductance up to a saturation pressure. The device may be used either as a combined switch and amplitude control or may be used in associated with one or more capacitors to provide either a high pass or low pass touch-control audio filter. In a totally polyphonic instrument a tone generator and touch-control filter are respectively associated with and responsive to each key depression, the output signal from each activated filter being coupled preferably to audio mixer circuitry.

Abstract: A shoe provided with a plurality of keys on the underside thereof which when depressed will produce various musical tones by means of an electronic circuit provided inside the shoe.

Abstract: A keyboard of an electronic musical instrument incorporates a plurality of variable capacitors, one for each key, with one conductor of each capacitor being connected for movement with an individual key of the keyboard toward and away from the other conductor, so as to vary the capacitance of the capacitor in accordance with the force with which the key is depressed.

Abstract: A keyboard arrangement in electronic musical instrument comprising playing keys movable to cover a predetermined distance in normal play and also being able to move farther in excess of said distance in accordance with the pressure applied to the keys, a movable arm arranged at position corresponding to each key at its depressed position, and a sensor means provided for said arm to detect the amount of the excessive distance covered by the movable arm and the speed thereof to generate a signal to be used for the control of expression such as tone volume, tone color and the like.The keyboard arrangement preferably further includes a deformable cushion means normally nondeformingly contacting, at its upper end, the bottom surface of the movable arm member during the normal movement of the positionally corresponding key but is deformed when the key makes a movement in excess of the normal distance to be covered by the key.

Abstract: This invention provides an electronic musical instrument comprising a keyboard circuit for producing a pitch determining voltage signal representing the note of an operated key, a voltage controlled oscillator for producing a tone signal having a tone pitch determined by the pitch determining voltage signal, and a voltage controlled lowpass filter for imparting a desired tone color to the tone signal. The voltage controlled lowpass filter is responsive to the pitch determining voltage signal from the keyboard circuit to control the cutoff frequency of the voltage controlled lowpass filter in such a manner that the harmonic content of a higher tone signal is decreased from that of a lower tone signal.

Abstract: This invention relates to a voltage controlled type electronic musical instrument comprising a keyboard section for generating a pitch determining voltage signal and a trigger signal upon key operation, a voltage controlled tone signal generating circuit including a voltage controlled oscillator, voltage controlled filter and voltage controlled amplifier for generating a tone signal in response to the pitch determining voltage signal and control wave generating circuits responsive to the trigger signal for generating control waves coupled to the voltage controlled oscillator, voltage controlled filter and voltage controlled amplifier. The pitch determining voltage signal is coupled to the voltage controlled amplifier so as to control the gain thereof, thereby decreasing the volume of musical sounds at higher frequency from that of musical sounds at lower frequency.

Abstract: A musical instrument is disclosed which is constructed of a group of taut strings arranged to be strummed, each string being connected to operate an analog switch capable of producing a graduated signal that is directly proportional to the amplitude of vibration of its string, an extrinsic sound source in circuit with each analog switch, the sound source having a variable volume which is varied directly proportional to the strength of the signal from the analog switch, a number of switch means arranged in a keyboard, each of which may close the circuit to one or more preselected sound sources for which the switch means are closed and the strings are vibrating.

Abstract: A touch responsive sensor for an electronic keyboard musical instrument of a variable capacitor type, which comprises a pair of electrodes spaced apart from each other, and an intermediate electrode interposed between the pair of electrodes and separated from each of the pair of electrodes by a dielectric. The intermediate electrode is movable from near one of the pair of electrodes toward the other of the pair of electrodes in accordance with the movement of each playing key of the electronic musical instrument. Thus, in the course of a key depressing movement, first and second touch responsive controlling signals are derived from, respectively, between the one of the pair of electrodes and the intermediate electrode and between the other of the pair of electrodes and the intermediate electrode in accordance with the variation of capacitance produced therebetween.

Abstract: The embodiment of the invention disclosed herein is directed to an electronic musical instrument of the keyboard type used to electronically reproduce piano sounds. The circuit has means to vary the amplitude of the piano voice in response to the velocity of the downward movement of the key. Means are provided for producing a fundamental square wave frequency and the second and fourth harmonics thereof, in response to the actuation of a given key on the keyboard. One circuit arrangement includes means for combining the fundamental frequency and the second and fourth harmonics in a predetermined time relation to produce the zero, attack, peak, and decay characteristics of a piano voice as actually produced by a piano string.