I recently found the OpenBSD songs, and the artists say that they are part of OpenBSD, logically as well as license-wise. And OpenBSD is licensed under a three-clause BSD license which is GPL compatible - that means I can record and publish it here!
This is the OpenBSD 3.6 release song: Pond-erosa Puff, written about people who make something free and suddenly decide to go the unfree path.
Many thanks to all you OpenBSD guys!
Your license is a bit too weak for my taste, but damn, it's free - and your code is as good as your songs!