I'm no expert, but google on Cass Meurig and cwrth and trac - you'll be amazed what you find. Besides Cass' cwrth cd, my recommendations are the 2 "best of" Plethyn cd's from Sain or wherever you can get them, and both the cd's on Tant Records.
I also recommend that you start listening to Frank Hennessy's archived Celtic Heartbeat on Radio Wales - unless you want to start learning to siarad Cymraeg!
Keep your Sol Hoopi ----- let us know how you like the Welsh music.
Chris yn Wheaton, IL