The heavy, psychedelic acid rock of Iron Butterfly may seem dated to some today, but the group was one of the first hard rock bands to receive extensive radio airplay, and their best-known song, the 17-minute epic "In-A-Gadda-Da-Vida," established that more extended compositions were viable entries in the radio marketplace, paving the way for progressive AOR. The track was written by vocalist, organist, and bandleader Doug Ingle, who formed the first incarnation of Iron Butterfly in 1966 in San Diego with drummer Ron Bushy. After the group moved to Los Angeles and played the c...