Automatic playing musical instrument

A system for recording musical performances for an automatic playing musical instrument comprising:

• a plurality of keys;
• key information generating means, having a small plurality of channels, for continuously generating key information data corresponding to depressed keys among said plurality of keys, each of said depressed keys being assigned to one of said channels;
• change detecting means for detecting a change in said key information data, said change detecting means comprising:
• (i) memory means having a first and second memory areas,
• (ii) a clock pulse generator for generating clock pulses at regular intervals,
• (iii) means for writing data from all channels of said generating means which contain key information data of completely depressed keys into said first memory area upon the occurrence of each clock pulse,
• (iv) means for detecting any difference between said key information data written into said first memory area and key information data previously stored in said second area, and
• (v) means for then transferring said key information data written into said first memory area to said second storage area and for discarding key information data previously stored in said second memory area;
• counting means for counting the number of said clock pulses since the last detection of a difference in said key information data;
• a third memory area in said memory means for storing the count of said counting means;
• and
• event frame establishing means for transferring the key information data stored in said first memory area and the count stored in said third memory area to a fourth memory area in said memory means upon the detection of one of said differences.

A microprocessor controlled system for recording performance data of a keyboard musical instrument, comprising:

• control signal generating means for generating control signals at a regular clock rate,
• said microprocessor being operative in response to each occurrence of said control signals to perform a sequence of events including:
• (a) comparison of data designating all currently depressed keys of said instrument with like data representing which keys were depressed upon the last prior occurrence of said control signal, and
• (b) in the event a difference is detected by said comparison operation, of establishing an event frame of data including the new depressed key data and an event time, and
• counter means for counting said control signals, the contents of said counter means comprising said event time, and, in the case where difference is detected, said microprocessor thereafter clearing said counter means before occurrence of the next control signal.

A system for recording musical performances for an automatic playing musical instrument comprising:

• a plurality of keys;
• key information generating means for generating key information data corresponding to depressed keys among said plurality of keys, said key information generating means including first means for storing data representing the identity of each depressed key, second means for storing data representing the strength with which said key was struck and third means for storing data indicating that said key has been completely depressed;
• change detecting means for detecting a change of said key information data;
• measuring means for measuring the time interval between successive changes in said key information data and generating a time period data representative of said time interval;
• storing means for storing, each time one of said changes is detected, a musical performance data comprising said key information data and said time period data.