Tone generating method and device

For a given tone generating channel, tone waveform sample data corresponding to a plurality of sampling cycles (e.g., 100 samples) are arithmetically formed collectively. Once performance information such as MIDI event data is supplied to a tone generator MIDI driver (16) from an application program such as a MIDI sequencer software (31), the MIDI driver (16), in response to an input MIDI signal, assigns new tone generation to a designated tone generating channel of a tone generator task (20), and prepares tone controlling parameters to be set in the designated channel. The tone generator task (20) arithmetically forms tone waveform data by use of the tone controlling parameters and passes the tone waveform data to a CODEC circuit (26) functioning as an A/D converter. The program and a general-purpose operating system are sequenced and executed by a preemptive multitask management program.