Ditto Gareth's comment.

Most Welsh folksongs are published in books, at least the sort of folksongs that people at Mudcat would be interested in. The sheet music which does exist is largely for choirs. Most available publications are available through Gwales , which is the Welsh Books Council site. Of course, if you want a particular song, or type of song, you'd be better off being a bit more specific in this thread and we'll try to help.

sian, west wales