Abstract: A frequency multiplying system and method in which a time varying analog input signal is sampled and stored in a memory matrix at a predetermined rate. The signal thus stored is read out from the memory matrix at a different rate and reconstructed into a time varying analog signal. The storage rates and readout rates are controlled by a command signal generator including a master run-up generator run up at a first run-up rate and reset by the fundamental input frequency, the highest level at the output of the run-up generator being continually stored in a memory circuit. Slave run-up generators which cycle at frequencies corresponding to the storage and reading-out of the sampled information are reset upon coincidence of their levels with the level in the memory connected to the master run-up generator. The command signal generator may be in either digital or analog form employing either counters or integrators as run-up generators. The analog input signal may be processed by either digital or analog means.

Abstract: An electronic music synthesizer is disclosed in which the sound producing chain includes a voltage-controlled oscillator, band-pass filter, low-pass filter, and amplifier in which selected control currents are supplied to low impedance points within the synthesizer circuit from a resistor matrix. The synthesizer produces sounds approximating different acoustic musical instruments or having different tonal qualities by the application of a predetermined voltage to one of fifteen input columns of the resistor matrix with selected other columns being grounded. The currents provided by the resistor matrix in combination with other externally generated currents control the center frequency and bandwidth of the band-pass filter, the cutoff frequency of the low-pass filter, the gain of the voltage-controlled amplifier, the time constants of transient contour currents used to control the filters and amplifier, and the waveform produced by the voltage-controlled oscillator.

Abstract: An electronic synthesizer instrument incorporates bass pedals for the notes of the musical scale, together with foot control apparatus adapted to select and modify the tone quality of sounds produced by operation of the bass pedals. The foot control apparatus includes push button switches which are operated by the toe of an operator's foot, and slide controls which are positioned by the operator's foot. At least some of the switches are preset switches for selecting and controlling multiple combinations of the functional units of the synthesizer. The control state of the instrument is at all times indicated by readily observable indicating lights.

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 keyboard assignment system for a polyphonic electronic musical instrument employs a small number (typically ten or twelve) of output channels each capable of storing a note identification code used to control generation of a corresponding tone. Output channels are assigned and/or released during an assignment cycle initiated when any keyboard key is depressed or released. During the assignment cycle a keyboard switch matrix and an encoding matrix cooperate to provide sequentially on a data buss note identification codes corresponding to depressed keys. The data buss is connected to all output channels. An identity signal is produced by each output channel which is storing a note identification code corresponding to any which appears on the data buss during the assignment cycle. Assignment logic, responsive to these identity signals, assigns an output channel to each newly depressed key on a priority basis, and releases each output channel which had been assigned to a key which is now released.

Abstract: An organ is described in which a small number of note generators, each comprising a binary divider, a group of keyers, and an envelope generator, serves an entire keyboard. Each note generator is selectively operable by multiplexed signals from a keyboard to produce either of two adjacent notes in any octave interval. Six of these note generators are provided for each manual of a spinet size organ. A seventh note generator, which is selectively operable to produce any of the notes available from the other six, is provided together with selection circuitry which causes the seventh note generator to augment any one of the other six which is called upon to produce two adjacent, or two octavely related, notes simultaneously. The pitch of all notes is determined by a set of top octave dividers which drive the binary dividers individual to each note generator.

Abstract: This invention provides an electronic musical instrument capable of producing plural musical tones simultaneously and also capable of controlling the pitch, tone color and volume of the musical tones in response to a player's finger touch on a key.Transducers capable of electrically detecting the finger touch, i.e. factors including pressure and speed of depression and displacement of the key, are provided for respective keys. Analog outputs of these transducers are sampled and multiplexed in time sharing by each of channels of the number equal to a maximum number of musical tones to be produced simultaneously, and each of the multiplexed signals is held in a corresponding one of condensers provided in the respective channels. The pitch, tone color and volume are controlled in accordance with the magnitudes of voltages held in these condensers. Suitable discharging circuits are connected to these holding condensers.

Abstract: The embodiment of the invention disclosed herein is directed to an electronic musical instrument of the keyboard type wherein the audio frequency signal information is derived from a multi-frequency generator formed by an electronic oscillator and a plurality of divider circuits, and wherein programmable divider circuits are associated with the various keys of the keyboard to generate associated tone signal information. The programmable divider circuits are formed on a large scale integrated circuit chip and enable alteration of the numerical divisor so that different tone signals can be obtained from the same electronic circuitry thereby enabling the same type of LSI chip to be used for many different circuit configurations. The LSI chip also provides a scanning circuit that scans an X--Y matrix switching arrangement to determine which one of a plurality of key switches is closed.

Abstract: This invention relates to a key system for electronic musical instruments, comprising a key circuit for forming control signals and control circuits for transmitting sound signals in response to the control signals. The key circuit produces the control signals in dependence on the position of a key and/or on elapsed time after depression of the key. Coupling means forming part of each control circuit modifies transient characteristics of the control signals whereby each control circuit can transmit notes in such a way that they each have a different build-up time. This enables the instrument to make a sound similar to that produced by a conventional non-electronic instrument.

Abstract: An electronic musical instrument comprising first and second musical tone signal synthesizing circuit arrangements including voltage waveform generators adapted to control first and second tone signals to be generated by the first and second musical tone signal synthesizing circuit arrangements. First and second memory groups including a plurality of waveform parameter controlling information memories are provided for control of the voltage waveform generators in the first and second musical tone signal synthesizing circuit arrangements. A memory selector includes the same number of preset switches as that of the memories in each of the first and second memory groups.

Abstract: An electronic musical instrument capable of producing a large number of harmonic contents with a small number of calculation circuits. A composite wave consisting of plural harmonics can be mathematically expressed as a multiplication of a factor including an order number of a harmonic and a factor or factors not including an order number of a harmonic. The instrument according to the invention utilizes this principle and produces a composite wave by first obtaining these two kinds of factors individually and thereafter multiplying them together.An example of the invention capable of calculating four harmonics simultaneously and another example capable of calculating two harmonics simultaneously are described.

Abstract: An electronic organ having voice selector means and a memory arrangement connected to the voice selector means which can be preset and which is under the control of preset switches. Each preset switch, when actuated, makes a respective preselected group of one or more voices effective while making the others of the voices ineffective. The preselected voices in any group can be varied at the will of the player.

Abstract: An electronic musical instrument capable of producing any desired combination of two tones of mutually different footage. According to the invention, such combination of tones can be produced from only two tone sources without providing tone sources of an equal number to a total number of footage to be coupled. In view of the fact that musical tone waveshape amplitudes of two coupled tones of different footage can be represented by a multiplication term of a sine wave content and a cosine wave content, these two waveshape contents are individually calculated and then combined to form amplitudes of a composite musical tone waveshape.

Abstract: A voltage controlled filter for an electronic synthesizer incorporates a plurality of individual voltage controlled filter stages connected in cascade with a variable feedback interconnecting the input and output stages. Each of the stages is controlled by application of a series of pulses, with the period between successive pulses determining the cutoff frequency of the filter. Application of pulses to the filter stages at different pulse repetition rates changes the cutoff frequency of the filter and modifies the relative amplitudes of different frequency components of an audio signal to be passed by the filter. The filter is suited for use with high level signals and provides an extremely wide dynamic range through a very high signal-to-noise ratio.

Abstract: A selective distortion control circuit for an electrical musical instrument employs a cathode or emitter follower valve having a load resistance that is selectively changed to provide either a clean or distorted output signal. The mutually in-phase clean input and distorted output of the valve are connected to opposite sides of a potentiometer of which the wiper provides a selectively proportioned mixture of clean and distorted signals. The relative amount of distortion may be selected, and once selected, the operator may readily choose between clean and distorted sound by changing the load resistance.

Abstract: A new, performer played, real time, multitonal, multimbral musical instrument consists of speed and force sensitive keys in which time domain multiplexing is used to find and associate one and only one tone generator, not otherwise busy, with any key that is depressed. The sound generator disclosed can provide very realistic simulations of the flute, oboe, trumpet, French horn, trombone through the provision of various types of modulations in amplitude and frequency of the various partials, as is characteristic of each instrument simulated, and filtered noise. Glissandi are provided from one note to another and are controlled from the pair of keys involved by the relative pressure with which they are depressed. For the nonpercussive tonalities, the speed with which a key is depressed, which is determined by differentiating the force, may be used to cause the attack transient to behave in a manner very characteristic of the instrument being simulated.

Abstract: A filter circuit for use in a musical instrument, such as an electronic organ, eliminating undesirable keying transients introduced into the signals provided by tone generators of the organ. The filter circuit includes a bandpass filter filtering from the keyed tone generator signals frequencies which are below and above the desired audio frequency spectrum of the output sound.

Abstract: Formant filtering is implemented in a computor organ of the type disclosed in U.S. Pat. No. 3,809,786 by eliminating, attenuating or accentuating certain Fourier components included in each waveshape amplitude computation. A set of formant filter factors define the formant filter passband as a function of frequency, logarithmic frequency or Fourier component order. As each constituent Fourier component is independently evaluated, the component amplitude is scaled by the appropriate formant filter factor. The resultant synthesized musical tone includes only Fourier components within the defined passband, so that formant filtering effectively is implemented without the use of an actual filter.

Abstract: An electronic musical instrument comprising a voltage controlled oscillator, a voltage controlled filter, a voltage controlled amplifier and envelope generators. An output envelope of the envelope generator has various parameters such as rise time and decay time or times. The envelope generator is of the voltage controlled type so that the parameters of the output envelope of the envelope generator are controllable in response to parameter controlling voltages from a parameter controlling voltage generator. In an attempt to enhance performance effects a switch circuit is provided, in accordance with the invention, to interchange between a rise time controlling voltage and a decay time controlling voltage which are both coupled from the parameter controlling voltage generator to the envelope generator.

Abstract: An electronic musical synthesizer generates tone signals coupled to a controllable bandpass filter and a controllable low-pass filter. A plurality of voice switches are individually selectable to couple preset control voltages to the filters, and to enable potentiometers which can be adjusted to generate control voltages to vary the frequency characteristics of the filters, control the octave of the tone signals, and to control a modulation oscillator. When a variable/preset switch is set to a preset state, the potentiometers are disconnected and auxiliary sections of the selected voice switch presets voltages for the oscillator, the octave circuit and the filters.

Abstract: An electric organ tone generating system in which each organ tone is generated by an individual independent oscillator with built-in computer means for individually tuning each individual oscillator in turn from a fixed crystal controlled reference oscillator. All the individual oscillators are of identical construction except for the tuning components of the oscillator.

Abstract: An electronic organ comprises memory means for memorizing in an analog manner the synthesizing ratio of repetitively occuring waves such as square waves for synthesizing qualities of sound in response to the signals from means for selecting qualities of sound (to be referred to as tablets hereinafter); a mixing circuit for adding the synthesizing ratio for each repetitively occuring wave when the means for selecting qualities of sound are selected; frequency dividers for dividing the oscillation frequencies of top octave generators, an indirect keying circuit for interrupting the current corresponding to the ratio of repetitively occuring waves in response to the repetitively occuring signal waveforms from the frequency dividers and intermittingly interrupting said current in response to on-off signals from a keyboard; a synthesizing circuit for combining the outputs from the indirect keying circuit into a group for each octave; a variable filter for changing the frequency characteristics electronically in re

Abstract: Tone lever switches deliver respective digital information signals each representing the manipulated state of each tone lever. A memory circuit memorizes plural sets of the information signals. A write/read control circuit determines whether the memory circuit memorizes the digital information signals from the tone lever switches or it delivers out the memorized digital information signals. A tone color control circuit controls the respective intensities of the tone signals of respective voices in accordance with the information signals read out from the memory circuit.

Abstract: The system of this invention is for use with an electronic musical instrument having a keyboard, and generally includes keyboard circuitry, audio waveform generators, envelope generators, static and dynamic filter circuitry and power amplifier and speaker apparatus. In accordance with one feature of this invention, the system comprises means for establishing different digital voice codes which are coupled to read only memories associated with the audio waveform generators, envelope generators and main voice circuitry. This voice code provides a limited number of program conditions to control such variables as audio waveform pulse widths, envelope attack, decay, sustain or release intervals, and instrument resonator control. Another feature of the present invention is concerned with the keyboard circuitry which operates from a digital key and octave code. Each code is sequentially interrrogated to determine if the corresponding key has been played.