A good thing to remember is that people do not sue other people over the few pence per year that is involved if a folkie records a few songs and sells the CDs at gigs. It is always worth putting "Trad arranged J Bloggs" on your records, it may result in a few bob coming your way eventually, instead of going into someone else's pockets. But it gives you no rights in the song, other than the arrangement on your own recording of it.
   The carthy/Simon controversy was interesting, and doubtless covered in other threads. The important thing to remember is that it is not a bone of contention between Martin Carthy and Paul Simon. Martin used to be niggled, but on mature reflection he has stated publicly that he isnt. Things are all square.