Musical instrument having automatic arpeggio circuitry

Claim 2

A musical instrument comprising: a. a series of tone producing means having frequencies corresponding to a chromatic musical scale; b. a keyboard having a left-hand portion and a right-hand portion, said keyboard including a series of keys connected to respective ones of said tone producing means to control the tone production; c. a set of key switches under the control of the keys of the left-hand portion of said keyboard connected for providing a keying potential; d. a series of control gates respectively interconnecting said key switches with musically corresponding ones of the tone producing means associated with the right-hand portion of said keyboard to control tone production independently of the directly associated keys; e. a selectably actuatable arpeggio switch connected for providing a potential; and f. means responsive to the potential from said arpeggio switch for successively applying spaced pulses of gating potential to said series of control gates.

Claim 3

A musical instrument according to claim 1 in which a plurality of octavely related ones of said control gates are connected together to receive keying potential simultaneously from the corresponding key switch.

Claim 4

A musical instrument according to claim 2 in which a plurality of octavely related ones of said key switches are connected together.

Claim 5

A musical instrument according to claim 1 in which diodes are located in series between said key switches and said control gates.

Claim 6

A musical instrument according to claim 1 in which said control gates are arranged in groups each including the control gates for controlling a plurality of chromatically adjacent ones of said tone producing means, the control gates of each group being connected together for receiving one of the pulses of the gating potential.

Claim 7

A musical instrument according to claim 5 including means so interconnecting pairs of chromatically adjacent groups of control gates that the control gate of one group of one of the pairs of groups, which gate is chromatically the closest to the other group of the pair, will receive the successive gating pulses for both of such groups.

Claim 8

A musical instrument according to claim 5 including means so interconnecting the control gate associated with the lowest frequency tone producing means of one group with the adjacent group associated with Lower frequency tone producing means that said control gate will also receive the gating pulse for said adjacent group.

Claim 9

A musical instrument according to claim 1 in which said pulse applying means comprises: a. a circuit, connected to be triggered by each cycle of operation of said arpeggio switch, for providing a potential that increases for a period of time at least as great as the desired arpeggio duration; and b. a cascade circuit having a series of stages arranged to be progressively responsive to such potential increase to provide said spaced pulses of gating potential.

Claim 10

A musical instrument according to claim 8 including means in the triggerable circuit for selectably adjusting said period of time.

Claim 11

A musical instrument according to claim 9 in which said adjusting means has a range of about 2 seconds.

Claim 12

A musical instrument according to claim 8 in which the triggerable circuit is an integrator circuit.

Claim 13

A musical instrument according to claim 8 in which the triggerable circuit produces a ramp potential which increases linearly with time.

Claim 14

A musical instrument according to claim 8 which includes a reset circuit under the control of said arpeggio switch and connected to the triggerable circuit for terminating the potential increase and hence the arpeggio before said period of time has elapsed.

Claim 15

A musical instrument according to claim 8 including a current amplifier connected between the triggerable circuit and said cascade circuit.

Claim 16

A musical instrument according to claim 8 in which said cascade circuit comprises: a. a series of normally charged capacitors connected to provide said pulses of gating potential in response to their being discharged; b. a series of low-impedance discharge paths for said capacitors respectively including normally nonconducting pulse gates under the control of the triggerable circuit; and c. means connected to said pulse gates and forming a part of said low-impedance discharge paths for rendering successive pulse gates progressively responsive to increasing control potentials.

Claim 17

A musical instrument according to claim 15 in which said capacitors are connected at one side to the keying potential and at the other side to a higher potential through a high impedance.

Claim 18

A musical instrument according to claim 15 in which said rendering means includes diode means between successive ones of said pulse gates.

Claim 19

A musical instrument according to claim 17 in which said diode means is a pair of diodes connected in series.

Claim 20

A musical instrument according to claim 8 in which said cascade circuit comprises: a. a capacitor in each stage arranged to be discharged through a low-impedance path and to be charged through a high-impedance path; b. said low-impedance path including a normally nonconducting pulse gate in each stage, and means for providing a potential reference between adjacent stages; c. said reference potential means being connected in series with each other; d. each said pulse gate having a control terminal connected to receive the increasing potential from the triggerable circuit; and e. connections between said stages and said series of control gates for transmitting said spaced pulses.

Claim 21

A musical instrument according to claim 8 in which the triggerable circuit includes an integrating transistor, and a capacitor connected between the base and the collector of said transistor.

Claim 22

A musical instrument according to claim 8 including a gate connected between the output of the triggerable circuit and ground, and connected to be rendered conductive in response to release of the arpeggio switch for instantly terminating any arpeggio.

Claim 23

A musical instrument according to claim 8 in which the triggerable circuit includes: a. an integrating transistor connected between the source of keying potential and said cascade circuit; b. a capacitor connected between the base and collector of said integrating transistoR; c. a control transistor connected between the source of keying potential and the base of said integrating transistor; and d. the base of said control transistor being connected to said arpeggio switch.

Claim 24

A musical instrument according to claim 8 in which the triggerable circuit includes; a. an integrating transistor connected between the source of keying potential and said cascade circuit; b. a normally charged capacitor connected between the base and collector of said integrating transistor; c. a normally conducting control transistor connected through a low-impedance path between the source of keying potential and a point between said capacitor and the base of said integrating transistor for charging said capacitor and for biasing said integrating transistor to be nonconductive; d. the base of said control transistor being connected to said arpeggio switch; and e. means providing a somewhat higher impedance path from said point to provide a discharge path for said capacitor; whereby closing of said arpeggio switch instantly biases said control transistor to be nonconductive, thereby enabling said capacitor to discharge at a rate determined by said higher impedance path, thereby progressively removing the bias from the integrating transistor to render it progressively more conductive during said discharge.

Claim 25

A musical instrument according to claim 23 in which said higher impedance path comprises an adjustable voltage divider.

Claim 26

A musical instrument according to claim 23 which includes a reset transistor connected in the charging path for said capacitor, the base of said reset transistor being normally biased to render the reset transistor conductive under the control of said arpeggio switch, whereby upon release of said arpeggio switch the normal bias on said reset transistor is instantly reestablished.

Claim 27

A musical instrument according to claim 1 in which said pulse applying means comprises an electrical circuit, responsive to each cycle of operation of said arpeggio switch, and including a series of sequentially operative stages for automatically providing said spaced pulses of gating potential.