"Wild Mountain Thyme" is in Vol. 1 of those little Ossian books, *Folksongs
& Ballads Popular in Ireland, under the title "Will you go, lassie go."
I think the book Ellen Klomps is referring to is *Folksongs of Britain and
Ireland*, ed. Peter Kennedy (London, New York, & Sydney: Oak Publications,
1975; reprint 1984), ISBN 0-7119-0283-6. I got this in paperback in ?1985,
for about 25 dollars US. It has 24 songs in Scots Gaelic, as well as
sections in Irish, Welsh, Manx, Cornish, and the French dialect of the
Channel Islands, as well as lots of songs in English. All the non-English
songs have parallel (not singing) translations. Each section has its own
introduction, with pronunciation guides listing what phonemes change to what
(although I'd still want to check with a native speaker before performing
them in public!). The tunes are melody only, with suggestions of chords.
hope this helps!
Alix Baillie
abaillie@mindspring.com