It's not as old, but in Wernor Herzog's documentary "Cave of Forgotten Dreams", an archeologist plays a 30,000 year old vulture bone flute. It even uses the pentatonic scale!
Some links about it:
https://www.youtube.com/watch?v=yUCBBDV2Tzk https://www.ethanhein.com/wp/2011/flute-of-forgotten-dreams/ https://www.npr.org/2009/06/24/105823127/a-little-flute-musi...