I kinda like the idea of offering some default musicoggzee said:As for a small standard mp3, feel free to suggest some and we might include it in the full distribution (but it must not be a copyirighted work)
But not copyrighted is a major problem.
I don't think you will find much fitting mp3s that way.
Even if the author no longer holds copyright the performer most likely will.
If someone really wants to look I think tracks that were recorded(!) in the 40s or earlier are a good starting point.
I see no reason not to use copyrighted music anyway.
If you can settle for copyrighted music I suggest everyone who wants some default music can search e.g www.jamendo.com for suggestions.