Clannad is the name of the group. Yes I agree they have good music as does Enya though she's a bit sleepy for my tastes. I like chances and mantras-'Green Tara mantra' with HH the Dalai Lama is awesome to meditate too! Yoga specific music also works.
I have nature sounds, or a Native American flute songs cd. I heard them at a concert, and loved them so much that I had to buy it.
i have a few reiki cd's that would probably work as background for yoga and meditation. merlin's magic~the heart of reiki steven halpern~chakra suite
when i meditate i usually listen to either the Mahavishnu Orchestra, various jazz (especially John Coltrane), and Sound Tribe Sector 9