So, after doing a bunch of research, I've finally figured out how to apply the creative commons licenses to my works here.
All my piano musings have a by-nc-sa license applied to them. That means that you can, without having to contact me and ask, download the pieces, and share them provided my name stays attached. You can also adapt them into your own works provided you apply a similar noncommercial license to the resultant work, and again give me attribution.
All my songs have a by-nc-nd license. That means that you can, without contacting me to ask, download and share my songs provided you keep my name attached. nd stands for "No Derivatives", meaning you can't adapt them into your own works. So it's a slightly more restrictive license.
You can of course feel free to contact me for more permissions on any of them, though. Some of the art musings have already had extra permissions granted to them (even though they are connected to my tunes, I let the artist have commercial purposes for the resultant art). Just contact me, I love to collaborate.
It was fun figuring out the technical end - in addition to each page having a creative commons badge, I was also able to give each song a friendly page name, such as http://curtsiffert.com/phoenixgrace for Phoenix Grace, and even embed the copyright information into the mp3 for each song. That means that as these songs propagate to file-sharing networks, the url for the song home will be spread out there as well, so people will be able to find me.