L-space has a full version of the song here. Edit: Found another version here. It was said by Wikipedia to be one of the better ones.
Dave Greenslade released a CD around April 2001 called 'From the Discworld' that contained several songs about the Discworld and its inhabitants. There is a specifically a song called 'A Wizard's Staff' which has a rather catchy melody. It can be purchased here but you may like to check out the CD section in your local library. They may be able to get you a copy to borrow.
