Iron Butterfly will forever be remembered as the first heavy metal band.Their moment of glory is the song "In-A-Gadda-Da-Vida," a 17-minute epicthat features a sinister guitar riff doubled on keyboards, bearded, manlyvocals and a drum solo that at times seems longer than the actual songitself. The ultimate 1960s acid rock song, it is difficult today tounderstand what an impact such music could have had on young listeners towhom the idea of heavy metal did not even exist. The rest of IronButterfly's catalog is littered with awful Flower Child psyche-pop andlame biker rock, but there are a few moments ("Iron Butterfly Theme,""Possession") where it becomes clear the band had an effect on the GratefulDead as well as the Doors, to name just two. As for true metal bands, DeepPurple is the next link the chain as far as that goes, lifting the idea ofguitar and keyboards played on top of one another directly from IronButterfly.