Doug Ingle, the lead vocalist, organist and primary composer of the band Iron Butterfly, has died at the age of 78.

The rocker’s passing was confirmed by his son, Doug Ingle Jr., via social media.

“It’s with a heavy heart & great sadness to announce the passing of my Father Doug Ingle. Dad passed away peacefully [Friday] evening [May 24] in the presence of family,” he wrote. “Thank You Dad for being a father, teacher and friend. Cherished loving memories I will carry the rest of my days moving forward in this journey of life. Love you Dad”.

Ingle was born in Omaha, Nebraska, but relocated to San Diego at an early age. His father, Lloyd, was a church organist, exposing the future rock star to music early in life.

Ingle co-founded Iron Butterfly in 1966, beginning in San Diego before moving to Los Angeles a year later. The psychedelic rock group released their debut album, Heavy, in January 1968. Six months later, they’d be rocketed to stardom on the back of their sophomore LP.

Released in June 1968, In-A-Gadda-Da-Vida became a multi-platinum triumph, spending 81 weeks in the U.S. Top 10. The album is best remembered for its title track, a sprawling explosion of psychedelic rock – written by Ingle – which originally lasted over 17 minutes in length. The radio version of the song, trimmed down to a tidy three minutes, became a Top 40 hit and remains one of the most influential tunes of its era. In the decades since its release, “In-A-Gadda-Da-Vida” has been covered by everyone from Slayer to The Simpsons.

Watch Iron Butterfly Perform ‘In-A-Gadda-Da-Vida’

Iron Butterfly soon found themselves touring with some of the ‘60s greatest acts, including the Doors, Cream, the Who, Buffalo Springfield and Janis Joplin. Ingle’s group was booked to play the legendary Woodstock festival in 1969, but ended up getting stranded at New York’s LaGuardia Airport.

Iron Butterfly released two more studio albums during Ingle’s tenure, 1969’s Ball and 1970’s Metamorphosis. They were never able to match the commercial success of In-A-Gadda-Da-Vida or its title track.

Doug Ingle Faced Massive Debt After Iron Butterfly

Iron Butterfly broke up in 1971, but reunited three years later. Ingle did not take part and was not involved in their two later LPs.

Shortly after his time in Iron Butterfly, Ingle discover that mismanagement and unpaid taxes had left him in serious debt.

“I was a child among men,” Ingle later recalled to the Los Angeles Times. “I was dealing with people who were competent but not necessarily (working) in my interest. I took the luxury of playing ostrich. I didn’t involve myself at the business level at all. I just went out and performed. It was, ‘Isn’t life great?’ Then everything crashed down. I still maintain life is great, but now I base it on something (real) rather than wishful thinking.”

Ingle was forced to sell his home and most of his possessions to pay off debts. He spent several years managing a recreational vehicle park in the Los Angeles National Forest.

In 1978, Ingle rejoined Iron Butterfly and toured with the band. He would continue to do so throughout the ‘80s and ‘90s. Ingle officially retired from performing in 1999.