1. A method comprising: executing in parallel sets of machine-code instructions with processing elements to generate digital waveforms for Musical Instrument Digital Interface (MIDI) voices present in a MIDI frame, wherein machine-code instructions in the sets of machine-code instructions are instances of machine-code instructions defined in an instruction set that is specialized for generation of digital waveforms for MIDI voices; aggregating the digital waveforms for the MIDI voices to generate an overall digital waveform for the MIDI frame; and outputting the overall digital waveform.