I got it working.
1. Grab the song you want, pop it in audacity and save it as a 16 bit signed microsoft wav, name it song.wav
2. Open your default skin xzp with xzp tool and extract it to a folder. Get XZP tool here:
3. Make a "Sounds" folder and put song.wav in it,
4. Open xzp tool and hit build on the extracted folder for a new xzp
5. Copy it to your Aurora skins folder on your 360
5. Switch to it in Aurora and restart
Worked for me