Automatic control apparatus for chords and sequences

• US 4,292,874 A
• Filed: 05/18/1979
• Issued: 10/06/1981
• Est. Priority Date: 05/18/1979
• Status: Expired due to Term

• Current Assignee: Gibson Piano Ventures, Inc.
• Original Assignee: Baldwin Piano and Organ Co (Gibson Brands, Inc.)
• Inventors: Jones, Edward M., Simmons, Carlton J. Jr.
• Primary Examiner(s): WITKOWSKI, STANLEY J
• Application Number:
  US06/040,107
• Time in Patent Office: 872 Days
• Field of Search: 84/1.01, 84/1.03, 84/1.13, 84/1.24, 84/1.26, 84/DIG. 2, 84/DIG.12, 84/DIG. 22, 84/DIG. 25
• US Class Current: 84/635
• CPC Class Codes: G10H 1/40 Rhythm
• CPC Class Codes: G10H 2210/361 Selection among a set of pre-established rhythm patterns
• CPC Class Codes: G10H 7/002 using a common processing for different operations or calculations, and a set of microinstructions (programme) to control the sequence thereof
• CPC Class Codes: Y10S 84/12 Side; rhythm and percussion devices
• CPC Class Codes: Y10S 84/22 Chord organs
• CPC Class Codes: Y10S 84/25 Pedal clavier

Abstract

Electronic and logic circuitry for an automatic tonal bass rhythm accompaniment feature and an automatic chord feature in an electronic organ. Automatic bass rhythm accompaniment produces a pattern of notes based upon a tonic note selected by the instrumentalist such that the desired musical effect is produced when the pattern of notes is combined with the notes being played by the instrumentalist. The electronic organ has stored in a memory various rhythm patterns which can be selected by the instrumentalist by closing rhythm switches. Electronic circuitry then causes notes for the selected rhythm pattern or patterns to be played automatically in response to the actuation of a pedal switch or keyswitch. The automatic chord feature of the present invention provides selectively major triad and dominant seventh chords or minor triad and diminished seventh chords automatically in response to the selection of a root note by the instrumentalist.

Claims

1. In an electronic musical instrument, an automatic rhythm generating device for generating selectable rhythm patterns of musical tones comprising:

an array of playing keys;

a plurality of rhythm switches for selecting rhythm patterns of tones, each rhythm switch in said plurality of rhythm switches corresponding to a rhythm pattern of tones and being operable to select the corresponding rhythm pattern;

rhythm counter means for providing timing signals to control the timing of the beats of the rhythm patterns generated by the automatic rhythm generating device;

memory storage means in which is stored binary data for each beat of each rhythm pattern, said binary data for each beat including trigger signal data indicating whether a trigger signal is required by each rhythm pattern and frequency deviation data indicating the value of the frequency deviation for the tone specified by each selectable rhythm pattern;

logic control circuit means responsive to the timing signals from said rhythm counter means for selecting said trigger signal data from said memory storage means in accordance with a rhythm pattern selected by operation of a rhythm switch in said plurality of rhythm switches and for providing a trigger signal during the depression of a playing key during each beat on which a tone is specified by a selected rhythm pattern, and for selecting from said memory storage means in accordance with a selected rhythm pattern the frequency deviation data corresponding to each beat on which a tone is specified by a selected rhythm pattern;

programmable signal generator means responsive to the actuation of a playing key in said array of playing keys and to said frequency deviation data selected by said logic control circuit means for generating a tone signal of a frequency related to the frequency of the actuated playing key by the frequency deviation value selected by said logic control circuit means for a selected rhythm pattern;

gating means for receiving said tone signal from said programmable signal generator means and for receiving said trigger signal from said logic control circuit means, said gating means passing said tone signal in response to the receipt of said trigger signal; and

audio output means for receiving said tone signal passed by said gating means, said audio output means converting said tone signal into an audible tone.

2. A device as claimed in claim 1 wherein said binary data stored in said memory storage means also includes damp signal data indicating whether a damp signal is required by each selectable rhythm pattern, and wherein responsive to the timing signals from said rhythm counter means said logic control circuit means selects said damp signal data from said memory storage means and provides a damp signal during the depression of a playing key in said array of playing keys during each beat on which damping is required by a selected rhythm pattern, and wherein also said gating means receives said damp signal from said logic control circuit means and damps said tone signal passed by said gating means in response to the receipt of said damp signal.

3. A device as claimed in claim 1 further comprising automatic chord generator means for generating a chord which is sounded by said audio output means in response to the actuation of a playing key in said array of playing keys.

4. A device as claimed in claim 3 wherein said automatic chord generation means further comprises:

musical key selector means for selecting seventh chords in response to actuation of predetermined ones of the playing keys in said array of playing keys;

tone source means for generating tone signals corresponding to the notes of the chords sounded in response to the playing of the keys within said array of playing keys; and

accompaniment gating means for receiving gating signals generated by said logic control circuit means in response to the playing of a key within said array of playing keys, said gating signals corresponding to the notes of the chord to be sounded in response to the key played, said accompaniment gating means passing to said audio output means said tone signals generated by said tone source means which correspond to said gating signals, whereby the chord is sounded.

5. A device as claimed in claim 4 wherein said chords are selectively major triad and dominant seventh chords and further comprising:

switch means for converting said major triad and dominant seventh chords to minor triad and diminished seventh chords.

6. A device as claimed in claim 1 wherein said array of playing keys includes an array of pedals.

7. A device as claimed in claim 6 wherein said logic control circuit means causes the automatic rhythm generating device to not begin sounding automatic rhythm patterns in response to the playing of a key in said array of playing keys until after a predetermined delay, thereby allowing the keys in said array of playing keys to be plated without initiating automatic rhythm patterns when the keys are depressed for less than the predetermined delay period.

8. A device as claimed in claim 2 wherein said memory storage means further comprises:

first register means in which is stored data which includes said frequency deviation data, said trigger signal data and said damp signal for each beat of each selectable rhythm pattern corresponding to one of the rhythm switches in said plurality of rhythm switches;

second register means for storing activity now data for the current beat, which includes one bit of data for each selectable rhythm pattern;

third register means for storing one bit of data for each of said rhythm switches;

fourth register means for storing frequency deviation data said damp signal data for the current beat of each of the rhythm patterns; and

fifth register means for storing activity next data for the current beat, which includes one bit of data for each rhythm pattern; and

wherein said logic control circuit means transfers activity next data for the preceding beat, which is the activity now data for the current beat, from said fifth register means to said second register means and then transfers activity next data for the current beat from said first register means to said fifth register means, and wherein responsive to each rhythm pattern selected by actuation of one of said plurality of rhythm switches said logic control circuit means sets a corresponding bit in said third register means to a predetermined state, and wherein said logic control circuit means transfers frequency deviation data and damp signal data for the current beat of each of the selectable rhythm patterns from said first register means to said fourth register means, and wherein said logic control circuit means performs a first logical AND operation on the bits stored in said fifth register means and the corresponding bits stored in said third register means followed by a logical OR operation on the result obtained from the logical AND operation, said logic control circuit means generating a damp signal when the result of said logical OR operation is in a predetermined state, and wherein said logic control circuit means selects from said fourth register means according to the result of said first logical AND operation said damp signal data required by the selected rhythm patterns on the current beat, and wherein said logic control circuit means selects from said fourth register means according to the result of said first logical AND operation said frequency deviation data required by a selected rhythm pattern on the current beat.

9. A device as claimed in claim 1 wherein until after a predetermined delay said logic control circuit means causes the automatic rhythm generating device to not begin sounding automatic rhythm patterns in response to the playing of a key in said array of playing keys, said programmable signal generator means generates a tone signal of the frequency of the actuated playing key, and said gating means receives said tone signal from said programmable signal generator means and passes said tone signal to said audio output means, whereby tones corresponding to rapidly played keys are inserted into the rhythm pattern selected by operation of a rhythm switch in said plurality of rhythm switches thereby breaking into the selected rhythm pattern temporarily while keys are rapidly played and resuming automatic rhythm generating responsive to the playing of a key which is played longer than the predetermined delay.

10. In an electronic musical instrument, an automatic rhythm device for generating a rhythm pattern of pedal tones comprising:

an array of pedals;

a plurality of rhythm switches for selecting rhythm patterns of pedal tones, each of said rhytm switches being operable to select a corresponding rhythm pattern of pedal tones;

trigger signal generator means responsive during the actuation of a pedal in said array of pedals for generating a trigger signal during each beat in which a pedal tone is required by a rhythm pattern selected by operation of one of said plurality of rhythm switches;

damp signal generator means responsive during the actuation of a pedal in said array of pedals for generating a damp signal during each beat in which damping of a pedal tone is required by a rhythm pattern selected by actuation of one of said plurality of rhythm switches;

code generator means responsive to the actuation of a pedal in said array of pedals for generating a binary code corresponding to the frequency of a pedal tone related to the frequency of the actuated pedal by a frequency deviation governed by the rhythm pattern selected by actuation of one of said plurality of rhythm switches, the frequency deviation being variable from beat to beat according to the rhythm pattern selected by actuation of one of said plurality of rhythm switches;

programmable pedal signal generator means for receiving the binary code from said code generator means and for generating a pedal tone signal of a fequency corresponding to the binary code;

gating means for receiving the pedal tone signal generated by said programmable pedal signal generator means, for receiving the trigger signal from said trigger signal generator means, and for receiving the damp signal from said damp signal generator means, said gating means passing the pedal tone signal in response to the receipt of a trigger signal, and said gating means damping the pedal tone signal passed by said gating means in response to the receipt of a damp signal; and

audio means for receiving the pedal tone signal passed by said gating means and for converting the pedal tone signal received to an audible pedal tone, whereby during each beat for which a pedal tone is required by a selected rhythm pattern a pedal tone determined by a selected rhythm pattern and related in frequency to the tone corresponding to an actuated pedal is sounded and damped according to the selected rhythm pattern.

11. A device as claimed in claim 10 further comprising:

an array of manual playing keys; and

mode switch means having two states for allowing the selection of either a first or second mode, said mode switch means deactuating said array of pedals when said mode switch means is in a first state and said mode switch means not affecting the operation of said array of pedals when said mode switch means is in the second state; and

wherein when said mode switch means is in the first state said code generator means is responsive to the actuation of a key in said array of playing keys and generates a binary code corresponding to the frequency of a pedal tone related to the frequency of the actuated key by a frequency deviation governed by the selected rhythm pattern, and wherein said trigger signal generator means and said damp signal generator means are responsive during the actuation of a key in said array of playing keys, whereby during each beat a pedal tone determined by a selected rhythm pattern and related in frequency to the tone corresponding to a key played in said array of manual playing keys is sounded and damped according to the selected rhythm pattern.

12. A device as claimed in claim 11 further comprising:

note played generator means for generating a note played signal in response to the actuation of a pedal when said mode switch means is in the second state, and for generating a note played signal in response to the actuation of a playing key when said mode switch means is in the first state;

second gating means for receiving the pedal tone signal generated by said programmable pedal signal generator means and for receiving the note played signal generated by said note played generator means, said second gating means passing the pedal tone signal to said audio output means in response to the receipt of a note played signal; and

wherein said audio output means receives the pedal tone signals passed by said second gating means and converts the pedal tone signal received to an audible pedal tone.

13. A device as claimed in claim 11 further comprising automatic chord generation means for generating chords in response to the actuation of a playing key when said mode selector means is in the first state.

14. A device as claimed in claim 11 further comprising:

memory means for causing the automatic rhythm device to continue generating a rhythm pattern of pedal tones once a playing key has been actuated when said mode switch means is in the first state; and

memory defeat switch means for stopping the generation of the rhythm pattern of pedal tones.

15. A device as claimed in claim 10 further comprising:

data register means for storing data for the rhythm patterns of pedal tones corresponding to said plurality of rhythm switches, said data register means containing data for each rhythm pattern and said data indicating whether a trigger signal or a damp signal is required for each beat of the rhythm pattern, said data register means also containing data indicating a frequency deviation value for each beat of each rhythm pattern; and

control means for causing said trigger signal generator means to generate a trigger signal during the actuation of a pedal in said array of pedals during each beat in which a pedal tone is required according to said data stored in said data register means for a selected rhythm pattern, said control means also causing said damp signal generator means to generate a damp signal during the actuation of a pedal in said array of pedals during each beat in which damping of a pedal tone is required according to said data stored in said data register means for a selected rhythm pattern, said control means also causing said code generator means to generate a binary code corresponding to the frequency of a pedal tone related to the frequency of the actuated pedal in said array of pedals by a frequency deviation of a value obtained from said data stored in said data register means.

16. A device as claimed in claim 15 wherein said data register means further comprises:

activity register means for storing one bit of data for each rhythm pattern on a particular beat, said bit for each rhythm pattern being in a first state when a trigger signal or damp signal is required by the rhythm pattern on that beat and said bit being in a second state when no trigger signal or damp signal is required for the rhythm pattern on that beat;

a rhythm register means for storing one bit of data for each of said rhythm switches, each of said bits being in a first state when the corresponding said rhythm switch has been actuated and said bit being in a second state when the corresponding said rhythm switch has not been actuated;

logic circuit means for performing during each beat a logical AND operation on the contents of said rhythm register means and the contents of said activity register means, thereby providing a set of bits corresponding to which of the selected rhythm patterns require a trigger signal or a damp signal on that particular beat; and

wherein said control means selects data from said data register means according to said set of bits to control whether to cause said trigger signal generator to generate a trigger signal, whether to cause said damp signal generator means to generate a damp signal, and selects data from said data register means indicating the frequency deviation value to be utilized by said code generator means to generate the binary code.

17. A device as claimed in claim 10 further comprising:

data register means for storing data for the rhythm patterns corresponding to said plurality of rhythm switches and data corresponding to which of said plurality of rhythm switches have been selected, said data register means containing data for each rhythm pattern indicating whether a trigger signal or a damp signal is required and the frequency deviation value for each beat of each rhythm pattern;

rhythm counter means for generating signals corresponding to each beat of the rhythmic pattern of pedal tones;

logic circuit means for receiving the signals generated by said rhythm counter means, said logic circuit means generating a first output signal when a trigger signal is specified by the data in said data register means for a selected rhythm pattern and a second output signal when a damp signal is specified by the data in said data register means for a selected rhythm pattern, said logic circuit means also generating frequency deviation output signals corresponding to the value of the frequency deviation specified by the data in said data register means for a selected rhythm pattern for the current beat; and

whereby, when a pedal in said array of pedals has been actuated, said trigger signal generator means generates a trigger signal in response to said first output signal from said logic circuit means, said damp signal generator means generates a damp signal in response to said second output signal from said logic circuit means, and said code generator means generates a binary code corresponding to the frequency of a pedal tone related to the frequency of the actuated pedal by a frequency deviation value corresponding to said frequency deviation output signals.

18. A device as claimed in claim 17 wherein said data register means further comprises:

instruction register means in which is stored data corresponding to whether a trigger or special damp signal is required for each beat of each rhythm pattern, data corresponding to the value of the frequency deviation and activity next data corresponding to whether a damp signal is required for the next beat of each rhythm pattern;

activity now register means for storing one bit of data for each of the rhythm patterns;

rhythm register means for storing one bit of data for each of said rhythm switches;

activity next register means for storing one bit of data for each of the rhythm patterns;

wherein during each beat said logic circuit means transfers activity now data for the current beat from said activity next register means to said activity now register means, and then transfers activity next data for the current beat from said instruction register means to said activity next register means, and interrogates said plurality of rhythm switches and for each of said rhythm switches which has been actuated to select the corresponding rhythm pattern sets a corresponding bit in said rhythm register means to a first state and for each of said rhythm switches which has not been actuated sets a corresponding bit in said rhythm register means to a second state; and

wherein said first output signal of said logic circuit means is the result obtained by said logic circuit means performing a logical AND operation on the bits stored in said activity now register means and said rhythm register means followed by a logical OR operation on the result of the logical AND operation.

19. A device as claimed in claim 10 wherein each rhythm pattern has a first variation and a second variation and further comprising means for selecting either said first variation or said second variation to be generated by the automatic rhythm generating device.

20. In an electronic musical instrument, an automatic chord and rhythm generating device for generating chords and rhythm patterns of bass tones comprising:

an array of playing keys;

a plurality of rhythm switches for selecting rhythm patterns of tones, each of said rhythm switches corresponding to a rhythm pattern of tones;

musical key selector means for selecting seventh chords in response to actuation of a playing key from predetermined groups of said playing keys, each predetermined group of playing keys being selectable by said musical key selector means and the particular seventh chords corresponding to each group of playing keys thereby being selectable;

trigger signal generator means reponsive to the actuation of a playing key and to the selection of a rhythm pattern by actuation of one of said rhythm switches for generating a trigger signal during each beat in which a tone is required by a selected rhythm pattern;

damp signal generator means reponsive to the actuation of a playing key and to the selection of a rhythm pattern by actuation of one of said rhythm switches for generating a damp signal during each beat in which damping of a tone is required by a selected rhythm pattern;

code generator means responsive to the actuation of a playing key and to the selection of a rhythm pattern by actuation of one of said rhythm switches for generating a binary code corresponding to the frequency of a tone related to the frequency of the actuated playing key by a frequency deviation value governed by the selected rhythm pattern, the frequency deviation being variable from beat to beat according to the selected rhythm pattern;

chord generator means responsive to said musical key selector means for generating a plurality of gate signals in response to the actuation of a playing key, each of said gate signals corresponding to a note of a chord, whereby the chord generated by said chord generator means is a seventh chord when the playing key actuated is one of a predetermined group of playing keys selected on said musical key selector means;

programmable signal generator means for receiving the binary code from said code generator means for generating a first tone signal of a frequency corresponding to the binary code;

note played generator means for generating a note played signal in response to the actuation of a playing key;

tone source means for generating tone signals corresponding to the notes of the chords generated by said chord generator means in response to the playing of a playing key;

first gating means for receiving said first tone signal generated by said programmable signal generator means and for receiving the damp signal from said damp signal generator means, said first gating means passing said first tone signal in response to the receipt of a trigger signal, and said first gating means damping said first tone signal passed by said first gating means in response to the receipt of a damp signal;

second gating means for receiving said first tone signal generated by said programmable signal generator means and for receiving the note played signal generated by said note played generator means, said second gating means passing said first tone signal in response to the receipt of a note played signal;

third gating means for receiving said tone signals generated by said tone source means and for receiving the gate signals generated by said chord generator means, said third gating means passing said tone signals received from said tone source corresponding to said gate signals received from said chord generator means; and

audio output means for receiving said first tone signal passed by said first gating means, said first tone signal passed by said second gating means and said tone signals passed by said third gating means, said audio output means converting said first tone signal received from said first gating means, said first tone signal received from said second gating means, and said tone signals received from said third gating means into audible tones.

21. The device as claimed in claim 20 wherein said chords are selectively major triad and dominant seventh chords and further comprising switch means for converting said major triad and dominant seventh chords to minor triad and diminished seventh chords.

22. In an electronic musical instrument having an array of playing keys, an automatic rhythm generating apparatus for generating selectable rhythm patterns of musical tones, said apparatus comprising:

a plurality of rhythm switches for selecting rhythm patterns of notes, each of said rhythm switches being operable to select a corresponding rhythm pattern to be sounded;

activity next register means for storing activity next data, the activity next data including binary data for each of the selectable rhythm patterns;

activity now register means for storing activity now data, the activity now data including binary data for each of the selectable rhythm patterns;

data register means in which is stored binary data for each of the selectable rhythm patterns, the binary data corresponding to activity next data for each beat of each selectable rhythm pattern and to a frequency deviation value for at least one beat of each selectable rhythm pattern;

logic circuit means for transferring the activity next data for the preceding beat from said activity next register means to said activity now register means and for transferring the binary data corresponding to whether trigger activity will be required during the next succeeding beat after the current beat from said data register means to said activity next register means;

trigger signal generating means for generating a trigger signal when the activity now data corresponding to a rhythm pattern selected by operation of one of said plurality of rhythm switches are in a predetermined state;

damp signal generating means for generating a damp signal when the activity next data corresponding to a rhythm pattern selected by operation of one of said plurality of rhythm switches are in a predetermined state;

binary code generating means responsive to the playing of a key in the array of playing keys for generating a binary code corresponding to the frequency of a tone related to the frequency of the key played by the frequency deviation value corresponding to the binary data stored in said data register means for the current beat for a rhythm pattern selected by operation of one of said plurality of rhythm switches; and

audio means for sounding a note corresponding to the binary code generated by said binary code generating means in response to a trigger signal generated by said trigger signal generating means and for damping the note being sounded in response to a damp signal generated by said damp signal generating means, whereby a note determined by a selected rhythm pattern and related in frequency to the note corresponding to a key played in the array of playing keys is sounded and damped by said audio means during each beat according to the selected rhythm pattern.

23. The apparatus as claimed in claim 22 wherein the binary data stored in said data register means also corresponds to whether special damp activity is required during each beat of each selectable rhythm pattern and wherein said damp signal generating means also generates a damp signal when the binary data stored in said data register means corresponding to whether special damp activity is required during the current beat of a rhythm pattern selected by operation of one of said plurality of rhythm switches are in a predetermined state, whereby a note is damped by said audio means during each beat for which special damp activity is required by a selected rhythm pattern.

24. An apparatus as claimed in claim 22 wherein for each beat of each selectable rhythm pattern for which trigger activity is indicated by the activity next data, the binary data stored in said data register means corresponds to a frequency deviation value.

25. An apparatus as claimed in claim 22 wherein the binary data stored in said data register means further corresponds to special damp activity for at least one beat of at least one selectable rhythm pattern and wherein said damp signal generating means also generates a damp signal when the binary data stored in said data register means corresponding to special damp activity during the current beat of a rhythm pattern selected by operation of one of said plurality of rhythm switches are in a predetermined state, whereby a note is damped by said audio means during each beat for which special damp activity is required by a selected rhythm pattern.

26. An apparatus as claimed in claim 22 wherein the size of said data register means is minimized by storing in said data register means binary data corresponding to tonal activity only for those beats of each selectable rhythm pattern for which tonal activity is required in accordance with the activity next data.

27. An apparatus as claimed in claim 26 wherein the binary data corresponding to tonal activity indicates the frequency deviation values and special damp activity required for each selectable rhythm pattern and wherein said damp signal generating means also generates a damp signal when the binary data stored in said data register means corresponding to special damp activity during the current beat of a rhythm pattern selected by operation of one of said plurality of rhythm switches are in a predetermined state, whereby a note is damped by said audio means during each beat for which special damp activity is required by a selected rhythm pattern.

28. An apparatus as claimed in claim 22 wherein for a predetermined period of time after the playing of a key in said array of playing keys said binary code generating means generates a binary code corresponding to the frequency of the key played and said audio means sounds the note corresponding to the binary code generated by said binary code generating means, whereby tones corresponding to rapidly played keys are inserted into the rhythm pattern selected by operation of one of said plurality of rhythm switches thereby breaking into the rhythm pattern temporarily while keys are rapidly played and resuming automatic rhythm generating responsive to the playing of a key which is played longer than the predetermined period of time.

29. An apparatus as claimed in claim 28 wherein said array of playing keys includes an array of pedals.

30. In an electronic musical instrument having an array of playing keys, an automatic rhythm generating apparatus for generating selectable rhythm patterns of musical tones, said apparatus comprising:

a plurality of rhythm switches for selecting rhythm patterns of notes, each of said rhythm switches being operable to select a corresponding rhythm pattern to be sounded;

logic control circuit means for providing frequency deviation data corresponding to each beat on which a tone is specified by a rhythm pattern selected by operation of a rhythm switch in said plurality of rhythm switches and for providing a trigger signal when a key in the array of playing keys is played during each beat on which a tone is specified by a selected rhythm pattern;

programmable signal generator means responsive to the playing of a playing key in the array of playing keys for generating a tone signal of the frequency of the playing key played during a predetermined delay period and, after said predetermined delay period, for generating a tone signal of a frequency related to the frequency of the playing key played by the frequency deviation corresponding to the frequency deviation data provided by said logic control circuit means;

gating means for receiving said tone signal from said programmable signal generator means and for receiving said trigger signal from said logic control circuit means, said gating means passing said tone signal in response to the receipt of said trigger signal; and

audio output means for receiving said tone signal passed by said gating means and for converting said tone signal into an audible tone.

31. In an electronic musical instrument, an automatic rhythm generating apparatus for generating selectable rhythm patterns of musical tones, said apparatus comprising:

an array of playing keys;

a plurality of rhythm switches for selecting rhythm patterns of tones, each of said rhythm switches being operable to select a corresponding rhythm pattern to be sounded;

activity now register means for storing activity now data, the activity now data including one bit of data for each rhythm pattern selectable by operation of said plurality of rhythm switches;

rhythm register means for storing a bit of data corresponding to each of said plurality of rhythm switches;

data register means in which is stored binary data for each beat, for each of the selectable rhythm patterns for which the activity now bit indicates activity, the binary data corresponding to a frequency deviation value and to whether trigger activity and special damp activity is required;

activity next register means for storing activity next data, the activity next data including a bit of data for each of the selectable rhythm patterns;

logic circuit means for transferring the activity next data for the preceding beat from said activity next register means to said activity now register means, for transferring the binary data corresponding to whether trigger or special damp activity will be required during the next succeeding beat after the current beat from said data register means to said activity next register means, and for setting to a predetermined state a bit in said rhythm register means corresponding to each rhythm pattern selected by operation of a corresponding one of said plurality of rhythm switches;

trigger signal generating means for generating a trigger signal when a bit stored in said activity now register means and a bit stored in said rhythm register means, both corresponding to the same rhythm pattern, are in predetermined states;

damp signal generating means for generating a damp signal when a bit stored in said activity next register means and a bit stored in said rhythm register means, both corresponding to the same rhythm pattern, are in predetermined states and for generating a damp signal when a bit from the special damp data for the current beat stored in said data register means and a bit stored in said rhythm register means, both corresponding to the same rhythm pattern, are in predetermined states;

binary code generating means responsive to the playing of a key in said array of playing keys for generating a binary code corresponding to the frequency of a tone related to the frequency of the key played by the frequency deviation value for the current beat stored in said data register means, the frequency deviation value corresponding to a bit stored in said rhythm register means which is in a predetermined state; and

audio generating means for sounding a rhythmic tone determined by the binary code from said binary code generating means in response to a trigger signal from said trigger signal generating means and for damping the rhythmic note being sounded in response to a damp signal from said damp signal generating means, whereby a rhythmic note determined by a selected rhythm pattern and related in frequency to the note corresponding to the key played in said array of playing keys is sounded and damped during each beat according to the selected rhythm pattern.

32. In an electronic musical instrument having an array of playing keys, an automatic chord generator apparatus for generating musical chords, said apparatus comprising:

chord note register means having a bit position for each of a predetermined group of notes;

logic circuit means for detecting the playing of a key in the array of playing keys and for assigning a binary number corresponding to the key in the array which is detected as being played;

arithmetic means for performing arithmetic operations on the binary number to derive additional binary numbers corresponding to additional notes musically related to the note of the key detected by said logic circuit means;

selector means for setting bits in said chord note register means, the bits which are set by said selector means corresponding to the binary number assigned by said logic circuit means and the additional binary numbers derived by said arithmetic means; and

audio output means for generating and sounding the musical chord comprised of notes corresponding to the bits in said chord note register means which have been set to the predetermined state by said selector means, whereby musical chords are generated comprised of notes automatically selected from a predetermined range of notes in response to the playing of a key.

33. The apparatus as claimed in claim 32 further comprising:

musical key selector means for selecting which chords to be sounded in response to actuation of predetermined keys in said array of playing keys are to contain seventh notes, whereby when the playing of one of the predetermined keys is detected by said logic circuit means, said arithmetic means performs an arithmetic operation on the binary number assigned by said logic circuit means to derive a binary number corresponding to a seventh note and said selector means sets to a predetermined state a bit in said chord note register means corresponding to a seventh note, whereby one of the notes in the musical chord sounded by said output means is a seventh note.

34. The apparatus as claimed in claim 32 further comprising:

switch means for selecting minor chords, whereby when minor chords have been selected by operating said switch means and when the playing of a key in said array of playing keys is detected by said logic circuit means, said arithmetic means performs an arithmetic operation on the binary number assigned by said logic circuit means to derive a binary number corresponding to a minor note and said selector means sets to a predetermined state a bit in said chord note register means corresponding to a minor note so that one of the notes in the musical chord sounded by said audio output means is a minor note.

35. The apparatus as claimed in claim 32 wherein said arithmetic means further comprises:

adder means for subtracting two from the binary number assigned by said logic circuit means, whereby a binary number corresponding to the seventh note is obtained.

36. The apparatus as claimed in claim 35 wherein said adder means subtracts three from the result obtained by the subtracting two operation, whereby a binary number corresponding to the fifth note is obtained.

37. The apparatus as claimed in claim 36 further comprising:

switch means for selecting minor chords, wherein when minor chords have been selected by operating said switch means said adder means subtracts four from the result obtained by the subtracting three operation, whereby a binary number corresponding to a minor third note is obtained, and wherein when minor chords have not been selected by operating said switch means said adder means subtracts three from the result obtained by the subtracting three operation, whereby a binary number corresponding to a major third note is obtained.

38. The apparatus as claimed in claim 35 further comprising:

overflow adding means for adding twelve to a result obtained by a subtracting operation performed by said adder means if the result is outside of a predetermined range of values.

39. The apparatus as claimed in claim 32 wherein said arithmetic means further comprises:

switch means for selecting minor chords;

adder means for adding three to the binary number assigned by said logic circuit means when minor chords have been selected by operating said switch means, whereby a binary number corresponding to the minor third note is obtained, and for adding four to the binary number assigned by said logic circuit means when minor chords have not been selected by operating said switch means, whereby a binary number corresponding to the major third note is obtained.

40. The apparatus as claimed in claim 39 further comprising:

overflow adding means for subtracting twelve from a result obtained by an adding operation performed by said adder means if the result is outside of a predetermined range.