Gnarls Barkley is an alternative/soul group which formed in 2003 in Atlanta, Georgia, United States. The group consists of Cee-Lo Green (vocals) and Brian "Danger Mouse" Burton (multiple instruments). The group is best known for the international smash hit "Crazy". "Crazy" - which was their first single - debuted at #1 on the British pop charts on April 2, 2006. It was the first #1 UK single to be obtained solely through Internet downloads.