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: A touch operated capacitive switch for altering electrical signals controlling the mode of operation of an electronic musical instrument. The switch comprises a thin laminate having a non-conducting lamina sandwiched between a conducting touch electrode and a conducting guard electrode, each electrode having an electrical connector for connecting the switch to alternating electrical signals having substantially the same phase and amplitude to reduce the capacitance between the touch electrode and points of ground potential located in or on the instrument for increasing the sensitivity of the switch. The switch is non-conductively secured to the instrument with the guard electrode facing the instrument, such that the capacitance of the switch may be altered by touching the touch electrode.

Abstract: Disclosed is 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. The two counters are stopped by a clock control while the note is sounded and then the counters are enabled by the counter control to continue counting through the matrix until the next actuated key is located.

Abstract: Disclosed is 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 enable a corresponding keyer to transmit an audio signal from an audio oscillator corresponding to the played key to an output system and loudspeaker. The two counters are stopped by a clock control while the note is sounded and then the counters are enabled by the counter control to continue counting through the matrix until the next actuated key is located.

Abstract: An arpeggiator for an electronic organ, comprising a source of ramp voltage having selectively a slowly ascending and a slowly descending section or only a slowly ascending section followed by a rapid reset, an accordion-like voltage divider for said ramp voltage consisting of a cascade of diodes, each calling forth one of a group of three tone signals when conductive, or no tone signal if short circuited, circuits for determining which diodes shall be conductive and which short circuited according to which keys of an organ are actuated, the ramp voltage peaking when all conductive diodes have been ascendingly scanned by the ramp voltage, each conductive diode when scanned by the ramp voltage falling forth a gating signal for one of the tone signals called for by the actuated keys, in orderly sequence of tone signals.

Abstract: A piano key frame assembly comprising a rigid metal frame, preferably formed from aluminum tubing, for supporting the piano keys and action, the frame having a front rail, an intermediate balance rail and a back rail, the back rail mounting adjustment means for leveling the keys, the key frame having adjustable feet by means of which it is positioned and leveled within the piano case, the conventional key bed being replaced by relatively narrow key bed brackets extending along the opposite sides of the case on which the adjustable feet are supported, means being provided to align and maintain the key frame on the key bed brackets.

Abstract: Simultaneously played notes on a keyboard are automatically provided with different voice timbres. The assignment of voices to notes is by relative frequency-scale position within the chord. If four or more notes are played, the notes are scanned along the musical scale and the three lowest notes played and the highest note are sounded in different voices with the solo voice assigned to the highest note. Assignment of voices occurs automatically when fewer than four keys are played. One form of the system combines time multiplexed keying with priority coupling of the keying information to a plurality of voltage controlled oscillators through sample-and-hold memory circuits. Each oscillator has its own tone voicing circuits. In another preferred all-digital embodiment, the time division multiplex digital logic signals representative of the played keys are applied instead to a memory circuit and a comparator circuit.

Abstract: Means for improving the repetition characteristics of an upright piano action of the type having a hammer for each key, the butt of the hammer being pivotally mounted on a main action rail so that the hammer can be projected from an at-rest position toward a string striking position, a wippen pivotally attached to the main action rail and operatively connected to the key, a jack pivotally connected to the wippen for transmitting the action of the key and wippen to the hammer via the hammer butt to cause the hammer to strike the string when the key is forcibly depressed and a back check serving as an oscillation damper for the hammer. The means for improving the repetition characteristics comprises an adjustable spring and linkage assembly attached at its ends to positions of substantially equal operating displacement on the wippen and the hammer butt.

Abstract: A transposing electronic instrument wherein the clock frequency applied to control a top octave frequency generator is derived by comparing any single output of the generator with the response of a frequency reference circuit to that output, deriving a dc voltage representative of the difference in frequency of the input and output of the reference circuit and controlling the clock frequency from the dc voltage, thereby transposing all the outputs of the top octave frequency generator.

Abstract: An electronic organ in which all the tones of the musical gamut are obtained by operations on the output of a single tone signal source, utilizing digital techniques to divide the frequency of the tone signal by appropriate integers.

Abstract: A monophonic system includes means for voicing only tones derived in response to depression of a key associated with the highest pitched note when several keys are struck at approximately the same time, regardless of the order in which the keys are struck. If several keys are released at approximately the same time, only the tones derived in response to the highest remaining activated key are voiced, regardless of the release sequence. In response to the system being played legatissimo, voiced tones gradually shift in frequency, i.e., portamento is achieved. In response to the system being played staccatissimo, voiced tones shift in frequency in discrete steps.

Abstract: An apparatus for wrapping strings for musical instruments in which the various parameters influencing the quality of the string are accurately controlled, the apparatus comprising an elongated track mounting an opposing pair of heads having rotatable shafts to which the opposite ends of a core wire are fastened, the shafts being rotated in unison by a pair of electronically controlled stepping motors, means being provided to tension the core wire between the heads, the wrapping wire being fed into contact with the core wire by a vertically disposed feed arm suspended from an overhead carriage traveling lengthwise of the track member, the wrapping wire being fed to the feed arm from a source of supply and, as an incident of such feeding, a predetermined tension is applied to the wrapping wire, the feed arm including means for controlling the rate at which the feed arm advances and means for controlling the angle between the wrapping wire and the core wire, the track member also mounting adjustable anvils for f

Abstract: Modulation systems for electrical signals representing music in which synchronous vibrato and tremolo modulations are applied to a flute signal in one channel, the vibrator being produced by a bucket brigade modulator and the tremolo by a balanced modulator in cascade with the bucket brigade modulator, and in which in a second channel tones other than flute tones, and pedal tones, are separately treated to have independent vibratos, and in which balanced modulators for modifying the amplitude of the tone signals are concurrently controlled by a common expression voltage. In one modification flute signals are vibrato modulated in opposed phases, and passed via diverse filters to a common tremolo modulator. Provision is made for combining the inputs of the channels, the outputs of which are electroacoustically transduced by separated loudspeakers. Provision is made for slowly varying the frequency of a sub-sonic modulating oscillator, which is either turned off, or operates at about 1 or about 6 Hz.

Abstract: A stop tablet mechanism particularly suited for electric organs wherein a plurality of stop tablets lie in closely spaced apart side-by-side relation, the stop tablets being pivotally mounted in a supporting frame by means of locating ears which are maintained in positive pivotal contact with the frame by pairs of wire springs, the wire springs engaging cam defining laterally projecting shoulders on the tablets and performing the additional function of maintaining the tablets in either of two positions of use, the spring elements being configured to provide flexibly mounted detent points which coact with the noses of the cam surfaces to maintain the tablet in its desired position of use.

Abstract: A system of class intercommunication which provides:1. individual channels between a teacher andA. any student of the class, orB. any of several preselected groups of students of the class, orC. the entire class.2. provision for ensemble playing within one or more of the groups.3. provision for group instruction from audio aids, all under control of the teacher only.Programming is achieved by rotary group programming switches, which determine the character of the facilities, e.g., individual, audio aids, and ensemble, by interlocked group selection switches which enable selection of one group to the exclusion of the others, by further interlocked selection switches which enable selection of an individual student to be monitored or privately instructed, and by a switch which enables the teacher to provide any or all groups with instruction simultaneously. A minimum number of switch actuators is provided, physically grouped for easy access and control within the span of one hand.