Very cool! I hacked the exact same thing a while ago. Also with soundcloud integration (and some filters and stuff). I'll take a peek at the code when i get to my computer in the next days. Maybe there is something where i could contribute.
Here is the link to what I hacked back then: https://github.com/letier/boombox
I'm planning on doing a complete rewrite, when I finally find the time. This thing was build pretty quickly.
Yeah, sorry the repo is private until I get it cleaned up a bit. This has been built quite quickly as well ;)