Jump for sounding just like the original w/o lyrics

It's Hip To Be Square

Johnny B Goode on vibraphone.

Moonshine Bash makes the best use of Roland sound effects patches

EVERYBRE.MID sounds like it's an actual recording taken from a utopian dimension in which Sting was replaced by someone's electric pan flute.

The MIDI device makes a huge difference, and I think the Roland Sound Canvas is pretty much the top-tier in this case. People writing music would usually write it with specific hardware in mind, and if it was played on different (usually cheaper) devices it would sound like crap.

I remember the ridiculous jump in quality when we upgraded from a (original) Soundblaster to an Esoniq Soundscape. It was almost as big a jump as when we went from the PC internal speaker to the Soundblaster.

Speaking of which, why was the PC speaker sound quality of early 90s PCs so much worse than the C64 of the early 80s?

The PC speaker is single-channel only and controlled by the CPU, so most software would only bother turning it on or off for basic beeps. To actually make it play music or complex sounds would use up CPU cycles, taking away from the main application/game. I think you can only do square-waves, and it's always mono. If you had sound effects AND music you'd have to mix them at the data level with CPU code.

The 80s computers, in particular the C64, had dedicated off-CPU chips that could make more complex waveforms (triangle, noise) with relatively minor CPU management. They also had multiple channels so you could play music and sound effects and the sound chip takes care of mixing. I think most of these were stereo as well.

Short answer - Commodore computers were arcade game boards with a keyboard attached. PC's were sold as spreadsheet & word processing machines.