Iron Butterfly is an American psychedelic rock band best known for the 1968 hit "In-A-Gadda-Da-Vida", providing a dramatic sound that led the way towards the development of hard rock music. Formed in San Diego, California among band members that used to be "arch enemies", their heyday was the late 1960s, but the band has been reincarnated with various members with varying levels of success, with no new recordings since 1975. The band's seminal 1968 album In-A-Gadda-Da-Vida is among the world's 40 best-selling albums, selling more than 30 million copies.