| abstract |
An automatic rhythm programmer for an electrical musical instrument which provides electrical pulses for actuating musical voice generators according to predetermined rhythmic patterns, having provision for introducing any one of several predetermined variations into any basic rhythmic pattern and for automatically changing from one variation to another at a preselected rate. The programmer comprises a master oscillator, a first counter and an electronic commutator which periodically pulse in sequence a series of address lines in an integrated circuit read-only memory, which also contains a separate series of tracks for each basic rhythmic pattern, each track being in circuit with certain of the address lines and energized at predetermined times therefrom, each track also being connected to certain of the voice generators and operable to provide actuating pulses thereto. In order to provide pattern variations, the read-only memory further contains a series of track variation lines, each corresponding to a particular pattern variation, which can be energized either manually or periodically in sequence by a variation counter at a preselected rate, each track variation line being in circuit with certain of the tracks and operable when energized to cancel or enable certain actuating pulses to the voice generators, whereby the rhythmic patterns developed at the voice generators are varied either manually or automatically according to the energization of the track variation lines. |