[ILUG] Strip first three characters from filename

[ollie at eillo.org]

I have a ton of mp3 files that I'm currently sorting the id3 tags for.
Each filename starts with the tracknumber followed by an underscore.

e.g. 01_SONG_NAME_-_ARTIST_NAME_-_ALBUM_NAME.mp3

Because i have a unique separator between the SONG, ALBUM and BAND name '_-_'
i can use my audio tag software to populate the ID3 tag fields appropriately.

However the track number is separated from the band name by an underscore and the 
software isn't flexible enough to tell the difference.

So i need a shell script that will loop through a directory and
strip the first three characters from each filename.

Can this be easily done in shell?

If not i can do it in python but id rather not.

Cheers,
       Oliver.