Unless you lived under a rock during the first 10 years of the 21st century, you've heard a song by Gnarls Barkley - probably the band's hit "Crazy." The musical duo - comprised of multi-instrumentalist/producer Danger Mouse and rapper/vocalist Cee-Lo Green - makes modern music that hearkens back to '60s and '70s era vocal groups. Initially gaining fame from his mash up of Jay-Z's "The Black Album" and The Beatles' "The White Album" to form the appropriately titled "The Grey Album," Danger Mouse caught the attention of copyright lawyers and Damon Albarn of Blur and the Gorillaz, who asked Danger Mouse to produce the next Gorillaz album. Calling on an old friend from the '90s, Cee-Lo Green, member of Goodie Mob, Danger Mouse formed his most successful collaboration yet and dropped a highly acclaimed album "St. Elsewhere."