Let's not overhype those days. I had a P1 166MHz and playing an MP3 meant everything else would have to be closed, if I'd open Word the song would stutter. Not all modern processing power is wasted.

I could play mp3s on a 66Mhz CPU, though yes other tasks would make the playback stutter.

I was doing it on Win 95 or 98, maybe the OS was using more RAM than yours?

Possibly, I was on System 7.1.