Electronic musical instrument forming tones by wave computation

An electronic musical instrument comprising:

• time channel providing means for providing repeated cycles of a plurality of time slots, each correspondingly located time slot over the repeated cycles constituting each time-division-multiplexed time channel;
• tone formation assigning means for assigning to each one of said time channels tone formation of each one of musical tone signals to be formed respectively defining individual note pitches and tone colors;
• at least first and second signal computing means for computing in combination each said one musical tone signal per each said one time channel using at least two cycles of the time slots as a unit processing perid, in which in the first cycle of said at least two cycles said first signal computing means executes per each said one time channel a first sub-computation according to a first mathematical function to produce a first wave signal for the assigned said one musical tone signal whereas in the second cycle of said at least two cycles said second signal computing means executes per each said one time channel a second sub-computation according to a second mathematical function to produce a second wave signal for the assigned musical tone signal utilizing the result of said first subcomputation as an argument in said second sub-computation;
• and
• musical tone wave forming means for forming a musical tone wave signal having an individual note pitch and a tone color based on the result of said second wave signal.