Is there an album by the vitamin string quartet?

Yeah they are very cool! I have like 25 songs from them. Yes, they got albums, but I think that every album contains a single artist. I have 3 songs from The Killers, and their album name is "The Vitamin String Quartet Tribute To The Killers." Or you can try yourself and search for King of Leon at Itunes by VSQ (http://itunes.apple.com/us/album/vitamin-string-quartet-performs/id399303112) or 30 Sec to Mars at any web page (http://www.vitaminrecords.com/web/page.asp?pgs=product&catid=20&id=1437). Everytime I want to buy an album from them, the albums contain a single artist...