Jim Seals of the iconic 1970s singing duo Seals & Crofts died on Monday. He was 80.

No cause of death was released. The passing of Seals, who formed the musical pair with Darrel “Dash” Crofts in 1969, was confirmed by multiple friends and relatives online, including his musician cousin, Brady Seals.

“I just learned that James ‘Jimmy’ Seals has passed. My heart just breaks for his wife Ruby and their children,” the country singer wrote on Instagram. “Please keep them in your prayers. What an incredible legacy he leaves behind.”

Seals & Crofts helmed the era of soft rock, with a string of hit tracks in the ’70s including “Summer Breeze,” “Diamond Girl” and “Get Closer,” which featured Carolyn Willis. While none of their tunes reached No. 1, they did make it in the Top 10 of Billboard’s Hot 100 chart. “We May Never Pass This Way (Again),” “I’ll Play for You,” “Goodbye Old Buddies” and “You’re the Love” reached the adult contemporary chart’s Top 10.

Other singers also weighed in on Seals’ passing.

“I spent a large portion of my musical life with this man. We toured together, he and Dash invited us to sing on Seals and Crofts records, and we played with him for years,” wrote fellow musician John Ford Coley in a lengthy Facebook post. Coley — who was half of the singing group England Dan & John Ford Coley alongside Jim Seals’ brother, Dan, who died in 2009 — noted that while the two “didn’t always see eye to eye,” Coley called Seals an “enigma.”

“I thought he was a bona fide, dyed in the wool musical genius and a very deep and contemplative man,” Coley continued. “We didn’t always agree and it wasn’t always easy and it wasn’t always fun but it definitely was always entertaining for sure. Dan adored his older brother and it was because of Jimmy opening doors for us that we came to Los Angeles to record and meet the right people.”

“This is a hard one on so many levels as this is a musical era passing for me. And it will never pass this way again, as his song said,” he wrote, a nod to Seals & Crofts’ 1973 hit song.

Despite a breakup in 1980, Seals & Crofts reunited in the early ’90s and 2000s, but only produced one album after their initial claim to fame in the ’70s, “Traces,” in 2004.

Prior to their success as a duo, both Seals and Crofts were part of the group the Champs, most known for their hit “Tequila,” in which Seals played the saxophone.

Seals first took up the sax at age 13 after years of playing the fiddle that his oilman father bought him as a child, according to Variety. In 1952, Seals dominated the fiddle division of a contest while his own father won in guitar. Three years later, Seals played in a local band dubbed the Crew Cats until he met Crofts and was offered a spot in the Champs in 1958, staying in the group until 1965.

From there, the duo move to Los Angeles, joining yet another group – the Dawnbreakers – where they discovered the Baha’i faith through the band’s manager Marcia Day. In 1967, the pair converted.

Between 1969 and 1971, Seals & Crofts released three albums as a pair, with Seals playing the guitar and Crofts the mandolin. While those works went under the radar, “Summer Breeze” finally caught the attention of mainstream listeners in 1972.

After playing for oceans of fans who hooted and hollered as they performed, they juggled controversy in 1974 with their anti-abortion tune “Unborn Child” following the landmark Supreme Court decision Roe v. Wade.

Yet, not long after, the duo dispersed in ’80, as disco dominated. While Seals moved to Costa Rica and reportedly began a coffee farm and raised three kids, Crofts took his family to Mexico and then Australia. Seals moved back to the US and settled in Nashville. He suffered a stroke in 2017, although he had essentially retired from his musical career before that.