Happy Birthday today (Sept. 9) to Iron Butterfly founding member, organist, primary composer and lead vocalist Doug Ingle. He turns 70. Most famously, he wrote the band's biggest hit 'In-A-Gadda-Da-Vida'.

The song clocks in at just over 17 minutes and is considered significant in rock history as one of the early transitions of psychedelic rock into heavy metal along with music by bands like Blue Cheer, Jimi Hendrix, and Steppenwolf.

Doug Ingle left Iron Butterfly in 1971 and has toured with his former band members on and off throughout the years.