Pedal tone generator having means for automatically producing tone patterns based on tonic note

Claim 1

Pedal tone generating apparatus for an electronic organ having a first plurality of pedal keys each associated with a different note of a musical scale, said apparatus comprising, in combination: high frequency generator means for normally producing the lower of at least two octavely-related high frequency pulse signals, a variable divider coupled to said generator means for dividing the frequency of a selected one of the high frequency pulse signals by one of a multiplicity of divisors according to one of a multiplicity of multi-bit logic code words applied to control terminals thereof, said logic code words corresponding to said divisors for producing at two output terminals of said divider octavely-related output tone signals corresponding to tones of a musical scale, first binary encoding means coupled to said pedal keys for producing in response to actuation of a given pedal key a key sense pulse and one of said first plurality of different four-bit digital words uniquely representing the note associated with the actuated key, rhythm logic means having a second plurality of output terminals each associated with a different note of a musical scale for storing at least one rhythm pattern and operative when activated and enabled to produce at each of said output terminals a predetermined pattern of pulses, second binary encoding means coupled to the output terminals of said rhythm logic means for producing when actuated one of said second plurality of different four-bit digital words uniquely representing the musical note associated with the output terminal at which a pattern pulse is present, the digital words representing the different musical notes associated with the output terminals of said rhythm logic means being the same as the digital words that represent corresponding ones of the musical notes associated with said pedal keys, means for applying said key sense pulse to said rhythm logic means and to said second binary encoding means for enabling said rhythm logic means, when activated, and for enabling said second binary encoding means, binary adder means coupled to said first and second binary encoding means for combining the four-bit digital words produced by said first and second binary encoding means and generating at output terminals thereof a four-bit digital word coded in the duodecimal system of counting representative of the pitch of an output tone determined by the four-bit words produced by said first and second binary encoding means, said binary adder means including logic means coupled to said high frequency generator means for causing said generator means to produce pulse signals of a frequency other than said lower frequency whenever the sum of said four-bit words exceeds the equivalent of the number twelve, and decoder means coupled to the output terminals of said adder means and to the control terminals of said variable divider for generating and applying to said variable divider a logic code word corresponding to the four-bit binary word generated by said binary adder means.