Jack’s Mannequin started as the side-project of Andrew McMahon, the vocalist, pianist, and main songwriter of the band Something Corporate. It then became McMahon’s main project. Jack’s Mannequin was based in Orange County, California. The name Jack’s Mannequin originated from one of McMahon’s songs called Dear Jack, which was written about a friend of his whose brother was diagnosed with childhood leukemia. Andrew himself was diagnosed with leukemia on June 1 Read more on Last.fm