I start making flutes and drums out of the other leftover cow stuff.
I can go into detail if that is what you want.
I take the ribcage of the cow and stretch his own skin around it so that it is very tight. I then sew the skin together. Bass drum. I can also make drums using smaller bones and leather using my thigh as a guide and then stretching the leather around my leg with the bones on it. I apply a resin (from a tree or something freaky like that) and let it harden. I stretch leather over either or both of the two sides depending on the sound I want. I can also make drums using tree trunks or any other object with that shape.
Flutes I just take bones and hollow out the marrow (which I eat for strength). Then I smash holes in the bone using a pointy rock. If I make a mistake at any point I just smash the bone and take the pieces that I think I can make into drumsticks for the drums and start doing that.
I save the smaller the sharp, broken bones. The ones that are hollow and pointed with a hole at the end I fill with ink and start drawing on the scraps of cowhide that are otherwise too small to use in my clothing.