Handbrake turn......................................

Your mp3's were a file on the desktop?

That was a short cut to a folder somewhere.
You've probably lost the short cut not the files, that's why they aren't showing on Undelete.

The short cut won't show in Un delete, the files could still be around.

Go to;
"START"
"Search"
"Search for music"

put in *mp3 (doesn't have to be in red!) then press "SEARCH"

If all the music shows, it's still there.

.