@QuercusMax 4d
The first percussion instruments were almost certainly either rocks or sticks banged together. The sticks were presumably used just like claves (https://en.wikipedia.org/wiki/Claves).
@dheera 4d
> lot of room for error

I mean, when you have all day and nothing to do sitting around in your cave, you can make a lot of flutes and hopefully one will be error-free.