I've been picking up round rocks in indian camps for sixty years. Here are some possibilities for uses of such. Three of them strung together produces a bolo, two of them incorporated into an oak handle makes a handy head-knocker and a small one mounted on a handle makes a effective drum stick. Anthropologists agree that man's first musical instrument was probably of a percussion type and may have been anything from banging two rocks together to beating on a hollow log with a club. There is no way to know if Clovis man made and used drums but if he did I kind of like to believe that it may have looked like this.