This video, via ed1269, demonstrates music making with the Intellivision ECS (Entertainment Computer System).
In the early 80’s, a 49-key Music Synthesizer keyboard was introduced for the system, allowing it to be used as a basic polyphonic synthesizer.
I still have three variations of the intellivision 🙂
6 channels was pretty amazing back then… and it has the ”Guitar Hero” interface :-O
The AY (and YM) chips could actually sound better (even though the chips are simple), because you could do many tricks in software (sort of half-softsynth).