Hence harmony was born. One apeman got wise to the notes and wondered what would happen if Og hummed one note and he hummed another. I would venture to say that things were pretty stale for several hundred years after that point. Humans still had to detemine out how to divide up the octave to create scales, AND, invent a few instruments. Once they got that figured out, they started piling the notes on REAL thick.
Orchestral music is evidence of that.
This pretty much brings us into recent history. The advent of recorded music changed everything. Up until that time, if you wanted to hear music, you had to hire a musician. Machines that mimic the qualities of real instuments to achieve uncanny results. And that's it.