Neither really. The original Mac sound hardware had
four *synthesis* voices,
which could be fed a waveform and act as a primitive wavetable synthesizer.
This produces four-note polyphony.
I don't know what you consider to be 'original Mac', but the Mac+ sound
hardware was a pulse-width modulator loaded from a spare byte in the
video RAM area at the end of each video line.
I think we're looking at this from different angles. I'm looking at it from
the view of what the Toolbox offers for music playback and synthesis; it
seems you and Jim are actually talking about what the Toolbox is driving.