Crazy

Crazy was released on 13 March 2006 as the debut single of Gnarls Barkley, produced by Danger Mouse. The writers are Danger Mouse (Brian Burton), Green, and Gian Franco and Gian Piero Reverberi, because the track samples Last Men Standing from the 1968 film Django, Prepare a Coffin and uses parts of its main melody and chord structure. The music was also inspired by Spaghetti Western film scores, in particular Ennio Morricone. Danger Mouse said the lyrics grew out of a conversation about how people will not take an artist seriously unless they are insane, and that Green turned it into the song, recorded in one take.

Green told Entertainment Weekly in 2016 that the beat played on loop for nearly six hours in the Atlanta studio while they talked about rock stars and authenticity, naming Ozzy Osbourne, Iggy Pop and Jim Morrison. He wrote the verses afterwards and recorded them in one take, and said the four pulses at the start were cues that let him count himself in. He added that he did not think much of it at the time.

The song leaked in late 2005 and got BBC Radio 1 airplay before release. In the UK it became the first number one based on download sales alone, held the top spot for nine weeks, and sold a million copies by January 2011. In the US it peaked at number two. It won the 2007 Grammy for Best Urban/Alternative Performance, and Rolling Stone ranked it first on its list of the 100 best songs of the decade. The video, directed by Robert Hales with inkblot animation by Blind, Inc., won two 2006 MTV Video Music Awards.