I like this picture because the guy before the drummer is a warrior, and that suggest that, in the end, humanity will find a way to channel its violence into art.
I do think that the first drummer was that hairy man of the early time who, after he defeated his enemy, used some kind of tool/weapon, be it a stick or a stone, to beat up the fallen man. And, discovering the pulse within his rage and his fright, he started to groove. The opponent became a pulp, but when the victorious man got up, he was the first drummer to walk the earth.