I recently posted four books of my old piano music on Smashwords. I've giving my old music away for free (which I'm hoping is a strategic move), but you can charge money if you like:
For this to work, I think you'd have to write a number of very similar pieces, give the first one away for free in order to get people trying it out, then charging for subsequent offerings.
Wot thee heck. A venue's a venue's a venue's a venue's a venue . . . keep on saying that until you self-hypnotise and fall down an endless blackened elevator shaft into the eternal abyss . . .