These music files are licensed under the Creative Commons By Attribution-Sharealike license version 3.0.
You may use them, redistribute them, and modify them according the terms of that license.

As far as attribution, mention that I, Eric Goodwin, created this stuff and hold the copyrights.  That's all I ask.  :)

The license terms may be found here:
http://creativecommons.org/licenses/by-sa/3.0/