Tone signal generation from fewer circuits

A tone generating apparatus, comprising:

• first tone signal generating means, said first tone signal generating means including a first predetermined plurality of oscillators, said predetermined number of oscillators being equal to a polyphonic number, each oscillator of said plurality of oscillators for generating a first tone signal of that component of tone components constituting a musical tone which has a tone-ON time of a first predetermined duration;
• first assigner means for assigning tone generation to one of said oscillators of said first tone signal generating means;
• second tone signal generating means including a second predetermined plurality of oscillators less than said polyphonic number, each oscillator of said second predetermined plurality of oscillators for generating a second tone signal of said tone components constituting a musical tone which has a tone-ON time of a second predetermined duration less than said first predetermined duration;
• a third tone signal generating means having fewer oscillators than said second tone signal generating means, for generating a third tone signal of said tone components constituting a musical tone which has a tone-ON time of a third predetermined duration less than said second predetermined duration;
• a fourth tone signal generating means having fewer oscillators than said third tone signal generating means, for generating a fourth tone signal of said tone components constituting a musical tone which has a tone-ON time of a fourth predetermined duration less than said third predetermined duration;
• said third and fourth tone signal generating means forming said second tone signal generating means;
• second assigner means for assigning tone generation to one of said oscillators of the third and fourth tone signal generating means;
• third assigner means for assigning tone generation to one of said oscillators of said third tone signal generating means;
• fourth assigner means for assigning tone generation to one of said oscillators of said fourth tone signal generating means;
• and
• adder means for synthesizing the signals output by assigned oscillators to produce a tone signal;
• whereby only three groups of oscillators are required to produce four tone signal components.