The jokey reference above to BC boxes for early music (tee hee hee) made me think of one amazing part of an amazing film that I saw earlier this year......
In 1994, a group of scientists discovered the Chauvet Cave in Southern France perfectly preserved for over 20,000 years and containing the earliest known human paintings. It will never be open for public visits however a film crew was allowed visits under strictly controlled conditions.
The film Cave of Forgotten Dreams (Werner Herzog) was mind blowing with the clarity and wonder of these magnificent paintings from pre-history, but there was a short sequence that left my jaw dropping, A whistle with finger holes made from animal bones had been found. An exact modern reproduction was made and a musician was able to play pentatonic tunes on it and it sounded in tune.

It looks like the pentatonic scale could have been around for 20,000 years. Get your mind around that!