"Brian Gaff" wrote in
:

Yes you need to have records of who played on what and when and of
course under what contract terms. As you know the guy who played the
sax solo on GerryRafferty's Baker Street was offered royalties on the
session but took a session fee to help pay his bills. Both Gerry and
Raf Ravenscroft are now dead, but many times during his life he came
to regret not going for royalties...
Brian


I was originally thinking of music that was originally analogue and is now
digital with all the information retrievable if you download it.