I remember being blown away by a DAC on a Commodore Pet. Unfortunately I don't think there are any videos. It wasn't common to own a video camera in 1980

http://www.zimmers.net/anonftp/pub/cbm/pet/audio/index.html

I'm not actually sure that's the correct software. All I remember is it sounding like real instruments back when I was used to simple beeps from the built in sound