SSH into your iPhone; browse to "var/mobile/application".
For every application, there are random numbers + letters generated. Try to open them all one by one, until you see a sub-folder "TPain.app". Go to "Documents/tracks".
So far, I could not find a way to upload my own music separately, but you can replace the existings with your own. Upload your own music (convert it to m4a format first using OJOsoft Audio Converter, et cetra). Then change the name to an existing one. Rather, those with no lyrics (e.g. 6-audio.m4a).
I have tried to edit the "json" files too, but no success. Yet I cannot find a way to have a new track with a new name.
P.S. If you use the built-in uploading system, it will compress the recorded song to m4a format that would significantly decrease the quality. Go back to recordings folder. You can retrieve the original "caf" files here.
If you found anything else about this, share it with us here.
Enjoy
The problem is here: access key, signature, expires (???)
e.g.
http://s3.amazonaws.com/smule-track-app.smule.com/tpain/9/audio.m4a?AWSAccessKeyId=AKIAIQXI4BRIF5SVJ4PQ&Sign ature=9692Tb
WcqpaqNlTFmrxdhdC8I%3D&Expires=12523 02624
audio_ts
1250299264
I've managed to create a new track (in "tracklibrary.plist", but it doesn't show up in the app list.