Iron Butterfly

One of the first bands to meld psychedelia with hard rock (and a key influence in the early days of heavy metal), Iron Butterfly scored a career- and era-defining hit with 1968's In-A-Gadda-Da-Vida. The title song became a staple on underground FM radio in its 17-minute LP version (which covered all of the album's second side), and a Top 40 hit in a three-minute single edit. The group never achieved another success on that scale, but it was more than enough to cement their legend, and their blend of trippy musical exploration and open-ended jams with a hard, distorted attack earned them a large and loyal audience. While their original incarnation ended in 1971, they reunited to record 1975's Scorching Beauty, and versions of the band were still performing into the 2020s.