The most important moment in music history is the moment the first person realised he/she could sing. The second most important moment is when some caveperson started tapping a beat.
After that, somebody notice that when you tap on various things, you get different sounds. Then there was the time that someone noticed the music nature makes. Then, some Island dude picked up a conch shell and blew into it: the creation of wind instruments. String instruments were another pleasant accident; how did that happen? No modern artist or composer is as important because without the caveguy pounding on a log with a stick, or that bird singing in the tree, they wouldn't have done anything at all.