US 4,300,430 A · Chord recognition system for an electronic musical instrument

Abstract

A chord recognition system for an electronic musical instrument, namely an electronic organ. A shift register receives data information from the keying lines of selected playing keys. The pattern of the received data is compared against selected normalized chord patterns in a program logic array to determine if the note input sequence is in a known musical relationship such as major, minor, minor sixth, seventh or others. A chord logic circuit receives the information from the programmed logic circuit and further reduces the information to output signals indicating a major, minor, or seventh chord and a pattern found signal. If no chord pattern is detected in the input data sequence, the register shifts the data on its first input line to its last input line and all other data is transferred downward accordingly. A counter sequences at each shift of the data input information. The shifted data is now compared in the programmed logic array as described above. This operation is repeated until a pattern match is found or an entire shift cycle is complete. The type of chord being played is indicated by the output of the chord logic circuit and the root or alphabetic key of the chord being played is indicated by the output of the counter. Each step of the counter indicates a different root or tonic note. Thus, the system recognizes normalized chord patterns and tracks the alphabetic key for recognizable chord patterns. The output from the chord logic circuit and the counter are used as inputs to other organ circuits such as a visual display circuit to illustrate to the organist the chord being played.

Claims25

Dependent claims

A chord recognition system providing a plurality of output recognition signals for use in an electronic organ having a plurality of lines with keying data and an output circuit responsive to at least one of said recognition signals, said chord recognition system comprising:

storage means for receiving said keying data and having a plurality of output signals corresponding to said keying data;
pattern identification means responsive to said plurality of output signals of said storage means for recognizing the relationship between said keying data and a normalized chord pattern;
said pattern identification means having a chord pattern output signal and a pattern found output signal if said keying data matches a normalized chord pattern;
control ciruit for providing a shift signal to said storage means for repositioning said keying data;
calculation means responsive to said shift signal for providing a data move output signal representing the number of shifts of said storage means;
and,
said control circuit responsive to said pattern found output signal of said pattern identification means for disabling said storage means and said calculation means.

4 more elements

A chord recognition system providing a plurality of output recognition signals for use in an electronic organ having a keyboard, a plurality of lines with keying data connected to said keyboard and an output circuit responsive to at least one of said recognition signals, said chord recognition system comprising:

register means having a plurality of input lines responsive to at least some of said plurality of lines with keying data and having a plurality of output signals corresponding to said keying data;
pattern identification means having a plurality of normalized chord patterns and being responsive to said output signals of said register means for comparing said keying data with said normalized chord patterns:
said pattern identification means providing a chord pattern output signal and a pattern found output signal when said keying data matches one of said normalized chord patterns;
a control circuit for providing a shift signal to said register for repositioning said keying data when no match is determined in said pattern identification means;
a counter circuit responsive to said shift signal for providing a data move output signal representing the number of shifts of said register;
and,
said control circuit responsive to said pattern found output signal of said pattern identification means for disabling said register and said counter.

4 more elements

Dependencies are inferred from the claim text.

Chord recognition system for an electronic musical instrument

Life of this patent

Chord recognition system for an electronic musical instrument

Life of this patent

Abstract

Claims25