From the recording Unfinished Surprise

First you make a mouthbow.
Then you sit in the dark in your little cabin and play it. It's amazing what comes out.
This cut is based on themes from Schubert's Unfinished Symphony and the Surprise Symphony by Haydn.
Usually the first few measures of a tune tell you what key you're in, and they use the harmonic tones of the chord built on the first note of the scale to do that. The mouthbow plays these notes and so very often I found the beginnings of tunes from all kinds of music.

It makes me feel so musical ... after all it happens inside your head!
I like that this shows how all music could have been played on the simplest of instruments by humans at all levels of technological and cultural attainment.
Primitive is not simple or stupid.