Iron Butterfly's Lee Dorman was found dead at his home on Friday, Dec. 21. The bassist, who also performed in the progressive rock group Captain Beyond, was 70.

According to TMZ, police arrived at Dorman's home at approximately 10 AM today and found the musician sitting in his car, apparently unresponsive. The site notes that Dorman had a history of heart trouble, and that authorities don't believe there is anything suspicious about his death.

Dorman joined Iron Butterfly before the release of their breakthrough album, 1968's 'In-A-Gadda-Da-Vida,' a massive hit best known for its 17-minute long title track. He performed on their next two records before they temporarily disbanded in 1971. He rejoined the reunited group in 1977, and except for a few hiatuses, performed with them regularly over the next three decades, leading the group to declare him their "driving force" and "a major influence on bass players for the past 30 years" on their official website.

Watch Iron Butterfly Perform 'In-A-Gadda-Da-Vida'