Abstract: A system for automatically generating an accompaniment note pattern and a bass pattern programmed therein by the player. The system includes a programmable microprocessor wherein two patterns, one sounding in the frequency range of the solo and accompaniment manuals and the other in the frequency range of the pedals, can be programmed into a programmable and reprogrammable memory by the player by means of a separate keypad or one or two octaves of keys on the regular keyboards. The patterns are programmed in without regard to key, and on playback, the microprocessor is responsive to the chord being played at that time on the accompaniment manual to transpose the read out patterns to a compatible key. Means are provided for phase locking simultaneously occurring notes of the two patterns if they are of the same or octavely related frequencies. This is accomplished by causing both notes to be taken off the same divider string if a match of pitch occurs.

Abstract: A percussion generator for an electronic musical instrument, such as an electronic organ, wherein the percussion generator is responsive to a time division multiplexed serial data stream produced by scanning the keys of the keyboard. A control pulse is produced each time that a new key on the keyboard is depressed, and this pulse, which has a duration equal to or greater than a plurality of scans of the keyboard, is employed to produce a burst of keydown pulses in the data stream. The percussion generator is responsive to the serial data stream and each of the aforementioned control pulses to produce keydown pulses in the appropriate time slots of the data stream in a plurality of successive sequences thereof and then terminate the keydown pulses even though the associated keys remain depressed.

Abstract: An electronic keyboard musical instrument comprising a multiplexed keyboard and a programmable microcomputer interfaced between the keyboard and a system of capture tone generators, and including means for causing phase locking between the tone generators. The loading circuitry for the microcomputer monitors the serial data stream and transmits only key change information to the microcomputer. The microcomputer controls the assignment and the assignment of tone generators for the accompaniment, solo and pedal manuals based on the key change information transmitted to it. In order to avoid cancellation between tones which are in octave or multiples thereof apart, the tone generators for each manual are phase locked with the other tone generators for that manual. Not only are the top octave synthesizers for each tone generator phase locked, but the divider strings are uniformly loaded so that they operate in identical states.

Abstract: An envelope generator for use in an electronic musical instrument, such as an electronic organ, employing a dual charge pump to form the attack and decay portions of the envelope. The envelope generator is adapted to be connected to the envelope control input of the keyer and the other input of the keyer is connected to a tone source. When the appropriate key of the keyboard is depressed, a source of input voltage is connected to the input of the envelope generator and a first charge pump incrementally transfers the input voltage to a capacitor over a first sequence of discrete time frames. The first charge pump circuit comprises a pair of electronic switches clocked 180.degree. out of phase and a capacitor connected between the juncture of the two switches and ground potential. The second mentioned capacitor is much larger than the first mentioned capacitor so that the charge transfer from one to the other takes place in a plurality of discrete steps.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation circuit of another manual, and tab footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of demultiplexer-keyers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide tones selected in accordance with the keydown pulses in the serial data streams to the voicing circuitry.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation circuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of demultiplexer-keyers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide tones to the voicing circuitry selected in accordance with the keydown pulses in the serial data streams.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation cirlcuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of demultiplexer-keyers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide to the voicing circuitry tones selected in accordance with the keydown pulses in the serial data streams.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation circuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of multiplexers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide tones selected in accordance with the keydown pulses in the serial data streams to the voicing circuitry.

Abstract: A high note data generator for use in electronic musical instruments such as electronic organs, pianos, and the like, wherein the time division multiplexed serial data stream is received, and a single data pulse is generated in the time slot of the first occurring pulse in the data stream. In organs wherein the manual is scanned from high to low, this will be the highest note played, which is convenient from the standpoint of converting polyphonic data to monophonic data for certain organ voicing or for use in solo manual fill note generation. Alternatively, the system can be utilized for converting a pulse spanning more than one time slot into a pulse occupying only a single time slot, which is coincident with the leading edge of the first-mentioned pulse. The system comprises a first latch having its clocking input connected to the serial data stream and one of its outputs connected to an input of an AND gate.

Abstract: An electronic rhythm generator which comprises a large read only memory having a plurality of rhythm patterns and rhythm break patterns programmed therein, player operated selector switches for selecting a rhythm pattern and a break pattern, scanning circuitry for sequentially addressing the memory to read out the stored rhythm pattern, and, when the break circuitry is activated, reading out the break pattern in place of or in addition to the rhythm pattern. The rhythm generator is contained on a single monolithic integrated circuit chip with the pattern selection being accomplished by an external multiplexer driven by an internally generated scan word. The break activation circuitry automatically corrects for improper matching of a rhythmically incompatible rhythm pattern and break pattern by either ignoring the break command or substituting a compatible break pattern in place of the selected break pattern.

Abstract: A fill note generator for use in electronic musical instruments such as electronic organs which include a keyboard having a solo portion customarily played by the right hand and an accompaniment portion customarily played by the left hand, and wherein the respective solo and accompaniment portions may be on separate manuals or on a single manual. A multiplexer scans the keys of the solo portion of the keyboard and generates a time division multiplexed solo data stream having keydown signals in discrete time slots for each actuated key of the solo portion of the keyboard. The keys of the accompaniment portion of the keyboard are interconnected so as to form twelve sets corresponding to the twelve pitches of the chromatic scale wherein the keys in each set are connected to a common output.

Abstract: A brass pulse keyer for electronic instruments such as electronic organs wherein the tone during attack is both amplitude modulated and pulse width modulated. The keyer is adapted for large scale integration and comprises a timing capacitor, an electronic switch connected between a source of charging potential and a capacitor and having a control terminal which is connected to the tone input, and a second electronic switch connected in series with the charge voltage, the first switch, and the capacitor and having a control terminal connected to receive the keying envelope. A comparator compares the potential on the capacitor with a reference potential and disables a gating circuit when a compare condition is reached such that the duty cycle may be controlled. As the keying envelope continues towards its maximum, the duty cycle decreases so that a more brilliant tone is achieved.

Abstract: An electronic music synthesizer capable of simulating a wide variety of musical effects, wherein the settings which create the various effects are hard wired on a plurality of selectable circuit boards so that programming of the instrument can be accomplished by the player with minimum effort. The synthesizer encodes a plurality of keys on the keyboard and selects a tone from the tone generator corresponding to the depressed key. This tone is fed through a chain of dividers to create the needed footages, which are then fed to voicing cards that create the different tone sources for the synthesizer. These tone sources are fed into a state variable active filter which modifies the timbre of the tone sources in order to achieve the desired frequency-related effects.

Abstract: A multiple pitch generator, in particular a chime generator, incorporated in an electronic organ of the multiplexed variety wherein the keyboard is scanned and a cyclically recurring serial data stream produced wherein keydown pulses appear in time slots corresponding to depressed keys of the keyboard. The chime generator produces a plurality of tones in response to the actuation of a single key of the solo keyboard, for example, wherein the tones are those necessary to closely simulate a chime sound. This is accomplished by sequentially passing the serial data stream containing the keydown pulse through a series of shift registers which insert in the data stream pulses in subsequent time slots corresponding to the next three lowest tones making up the chime.

Abstract: A circuit for an electronic organ for producing rhythmic patterns of notes in accordance with the selection of a chord in the accompaniment manual. The organ includes an accompaniment manual and a solo manual, either or both of which may be electronically scanned to develop a multiplexed data stream, and a chord generation circuit controlled by the accompaniment manual for sounding groups of notes in the accompaniment voices in response to the depression of one of the selected group of keys on the accompaniment manual. The circuit according to the present invention automatically sounds notes of the solo manual in a rhythmic pattern in response to the depression of one of the group of accompaniment manual keys by developing a logic pulse at the beginning of the top octave scan which is delayed in time to correspond to the time slot of the chord root note and subsequent notes of the chord. The amount of delay is controlled by pre-programmed patterns preselected by the musician.

Abstract: A brass keyer system for an electronic organ wherein the keyboard is multiplexed to produce a polyphonic serial data stream, which is then converted to a monophonic serial data stream containing a keydown signal in a time slot corresponding to the highest note played on the keyboard. The monophonic data stream is converted to a multiple bit binary word that is used by the tone generation and keying portion of the system to produce a rectangular wave tone corresponding in frequency to the highest depressed key and having amplitude and pulse width modulation on attack and decay so as to produce a brass tone. The monophonic serial data stream is demultiplexed by means of a recirculating delay loop which repetitively recirculates the keydown pulse for the depressed key. The number of recirculations of this pulse are counted by a first counter and the position of the pulse within the delay loop is registered by a second counter, which is synchronized with the multiplexer.

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 electronic organ employing the technique of multiplexing at least the solo portion of the keyboard and which includes an automatic chord playing circuit which plays chords in the solo voices corresponding to the accompaniment portion of the keyboard in response to depression of one of a predetermined group of keys of the accompaniment portion of the keyboard. The organ includes circuitry for automatically sounding notes corresponding to the chord selected in the accompaniment portion singly and sequentially from a selected end of the solo portion of the keyboard to the opposite end thereof, and further selectable to begin at one end of the solo manual proceeding to the other end thereof and sounding in reverse order back to the first mentioned end of the manual. If desired, the arpeggio run may be terminated at a selected point on the keyboard short of either end thereof.

Abstract: A circuit intended for use with electronic organs and, more specifically, with those electronic organs in which the keyboard switches are multiplexed, and which circuit provides a method for automatically sounding in succession either the natural notes (white keys) or the sharped notes (black keys) to create a glissando effect, beginning at either the upper, or lower, end of the solo manual and continuing down, or up, the manual at least until the note which is depressed by the player is reached. This simulates the effect of the organist running his finger from one end of the manual partially down, or up, the manual and reaching the previously mentioned depressed key.

Abstract: A method and apparatus for generating tones for an electronic organ in which a number of oscillators less than the tones in a scale are provided with the outputs thereof divided by selected divisors to produce a range of frequencies related to one another as the tones of the chromatic scale. The range of frequencies thus developed can be employed as, for example, the top octave for one or more of the organ keyboards and divided down to produce pitches corresponding to other octaves of the keyboards.