Malcolm:

Thanks for the Creighton link!

Nutty:

Wait! Before you get too diligent in your search: it's very kind of you, but I'm actually quite familiar with the various on-line sources for Robin Hood ballad texts, including the Bodleian.

At the moment, however, I'm specifically interested in finding sound recordings of the songs (preferably available for purchase by the public on CD).

I don't know how many Robin Hood ballads there are (rather difficult to know how to count, given all the later variants), but the major ballads in their earliest known forms (and plays & some novels) have been collected on the University of Rochester's excellent "Robin Hood Project" site, many with commentary by academics Thomas Ohlgren and Stephen Knight.

Cheers, Hester