Electrical musical instrument

Claim 2

An electrical musical instrument having a plurality of musical tones corresponding in frequency to the semi-tones of the equally tempered musical scale including an electrical tone signal source for each of the musical half-tones of said instrument, electro-acoustic output means electrically coupled to said sources of tone signals, a plurality of electrical switches, a different one of said switches being electrically coupled to each electrical tone signal source for selectively controlling excitation of the electroacoustic output means, and a source of electrical noise characterized by the improved construction wherein the source of electrical noise has means for generating a plurality of bands of electrical noise, said bands having center frequencies differing approximately by by half-tone steps from each other, and electrical circuit means responsive to each of the electrical switches for coupling a plurality of bands of electrical noise to the electro-acoustic output means, each of said plurality of bands having bands with center frequencies approximately equal to harmonics of that electrical tone signal source coupled to the same electrical switch.

Claim 3

An electrical musical instrument having a plurality of musical tones corresponding in frequency to the semi-tones of the equally tempered musical scale including an electrical tone signal source for each of the musical half-tones of said instrument, electro-acoustic output means electrically coupled to said sources of tone signals, a plurality of electrical switches, a different one of said switches being electrically coupled to each electrical tone signal source for selectively controlling excitation of the electro-acoustic output means, and a source of electrical noise characterized by the improved construction wherein the source of electrical noise has means for generating a plurality of bands of electrical noise, said bands having center frequencies differing approximately by half-tone steps from each other, and electrical circuit means responsive to each of the electrical switches for coupling a plurality of bands of electrical noise to the electro-acoustic output means, each of said plurality of bands having a band with a center frequency approximately equal to a harmonic of a group one through five of that tone signal source coupled to the same electrical switch and a band having a center frequency between adjacent harmonics greater than the fourth harmonic of said tone signal source.

Claim 4

An electrical musical instrument having a plurality of musical tones corresponding in frequency to the semi-tones of the equally tempered musical scale including an electrical tone signal source for each of the musical half-tones of said instrument, electro-acoustic output means electrically coupled to said sources of tone signals, a plurality of electrical switches, a different one of said switches being electrically coupled to each electrical tone signal source for selectively controlling excitation of the electro-acoustic output means, and a source of electrical noise characterized by the improved construction wherein the source of electrical noise has means for generating a plurality of bands of electrical noise, said bands having center frequencies differing approximately by half-tone steps from each other, and electrical circuit means responsive to each of the electrical switches for coupling a plurality of bands of electrical noise to the electro-acoustic output means, each of said plurality of bands having a band with a center frequency approximately equal to a harmonic of a group one through five of that tone signal source coupled to the same electrical switch and a band having a center frequency between adjacent harmonics greater than the fourth harmonic of said tone signal source.

Claim 5

In an electronic organ of the type having in tandem a tone signal generator, a key switch, a tone-color filter, a stop switch and an electroacoustic output system, the combination comprising a source of narrow bands of electrical noise, said bands having center frequencies respectively corresponding to at least a plurality of the semi-tones above the tone signal derived from said tone signal generator by closure of said key switch of the group consisting of the 12th, 19th, 24th, 28th, 29th, 30th, 32nd, 33rd, 34th, 35th, 37th, 39th, 41st, 42nd, 44th, 45th, 46th and 47th partial, and circuit means coupling said source to a point between said key switch and said stop switch for combining said bands with said tone signal.

Claim 6

In an electronic organ of the type having in tandem a tone signal generator, a key switch, a tone-color filter, a stop switch and an electroacoustic output system, the combination comprising a source of narrow bands of electrical noise, said bands having center frequencies respectively corresponding to at least a plurality of the semi-tones above the tone signal derived from said tone signal generator by closure of said key switch of the group consisting of the 12th, 19th, 24th, 28th, 29th, 30th, 32nd, 33rd, 34th, 35th, 37th, 39th, 41st, 42nd, 44th, 45th, 46th and 47th partial, and circuit means coupling said source to a point between said key switch and said stop switch for combining said bands with said tone signal.

Claim 7

The combination according to claim 3, wherein said source of narrow bands comprises a wide-spectrum electrical noise generator, a plurality of narrow-band-pass filters coupled in parallel to said noise generator, second circuit means coupled to said narrow-band-pass filters for mixing said bands, and an electronic gate between said second circuit means and said point between said key switch and said stop switch.

Claim 8

The combination according to claim 4, wherein a plurality of leveling resistors are located between respective ones of said narrow-band-pass filters and said second circuit means, and wherein a noise amplifier and a further leveling resistor lie in series between said gate and said point between said key switch and said stop switch.

Claim 9

An electrical musical instrument having a plurality of musical tones corresponding in frequency to the semi-tones of the equally tempered musical scale including an electrical tone signal source for each of the musical half-tones of said instrument, electro-acoustic output means electrically coupled to said sources of tone signals, a plurality of electrical switches, a different one of said switches being electrically coupled to each electrical tone signal source for selectively controlling excitation of the electroacoustic output means, and a source of electrical noise characterized by the improved construction wherein the source of electrical noise has means for generating a plurality of bands of electrical noise, each of said bands having a center frequency on a half-tone of the musical scale, and electrical circuit means for coupling different pluralities of said bands of electrical noise to the electro-acoustic output means responsive to each of the electrical switches, each of said pluralities of bands of electrical noise having center frequencies corresponding to a plurality of semi-tones above the frequency of the tone generator connected to said switch of the group consisting of the 12th, 19th, 24th, 28th, 29th, 30th, 32nd, 33rd, 34th, 35th, 37th, 39th, 41st, 42nd, 44th, 45th, 46th and 47th.

Claim 10

An electrical musical instrument having a plurality of musical tones corresponding in frequency to the semi-tones of the equally tempered musical scale including an electrical tone signal source for each of the musical half-tones of said instrument, electro-acoustic output means electrically coupled to said sources of tone signals, a plurality of electrical switches, a different one of said switches being electrically coupled to each electrical tone signal source for selectively controlling excitation of the electroacoustic output means, and a source of electrical noise characterized by the improved construction wherein the source of electrical noise has means for generating a plurality of bands of electrical noise, each of said bands having a center frequency on a half-tone of the musical scale, and electrical circuit means for coupling different pluralities of said bands of electrical noise to the electro-acoustic output means responsive to each of the electrical switches, each of said pluralities of bands of electrical noise having center frequencies corresponding to a plurality of semi-tones above the frequency of the tone generator connected to said switch of the group consisting of the 12th, 19th, 24th, 28th, 29th, 30th, 32nd, 33rd, 34th, 35th, 37th, 39th, 41st, 42nd, 44th, 45th, 46th and 47th.

Claim 11

The combination according to claim 6, wherein said source of narrow bands of electrical noise comprises a steady white-noise generator, and a plurality of parallel, narrow-band-pass filters coupled to said white-noise generator.

Claim 12

The combination according to claim 4, wherein each of the electrical switches has coupled thereto a second electrical switch, and said second switch is connected between the white noise generator and those band-pass filters associated with the tone controlled by said coupled electrical switch.

Claim 13

The combination according to claim 7, wherein the electrical circuit means includes an electronic gate connected between each plurality of narrow band-pass filters and the electroacoustic output means, each said gate being coupled to and controlled by the electrical switch to which said bands of noise are responsive.

Claim 14

The combination according to claim 6, wherein said source of narrow bands of noise comprises at least a first continuous white-noise generator, a second continuous white-noise generator, a first low-pass filter coupled to said first noise generator and having a normal and an inverted output, a first plurality of pairs of series-connected photocells, each pair of photocells in said first plurality being coupled across the normal and inverted output of said first filter, a second plurality of pairs of series-connected photocells, each pair of photocells in said second plurality being coupled across the normal and inverted output of said second filter, the total number of pairs of photocells in the first and second plurality being equaled to the number of bands of electrical noise, means for sinusoidally light modulating each pair of photocells at the frequency of a different semi-tone, the photocells of each pair being light modulated out of phase with each other, said electrical circuit means for coupling pluralities of bands of noise being connected to the junction between photocells in selected pairs of photocells.

Claim 15

An electrical musical instrument according to claim 6 wherein the source of electrical noise produces bands of noise having center frequencies from about 262Hz through about 8,372Hz.

Claim 16

A musical instrument according to claim 11 wherein the narrow bands of noise have Q-values (center frequency/3 decibel bandwidth) of about 13 to about 24, the Q-values increasing with frequency.