Variety is reporting that Jim Seals, who as part of the duo Seals & Crofts crafted memorably wistful 1970s hits like “Summer Breeze” and “Diamond Girl”, died Monday at age 80. No cause of death was immediately given.

Several friends and relatives confirmed the death. “I just learned that James ‘Jimmy’ Seals has passed,” announced his cousin, Brady Seals, a former member of the country band Little Texas, Monday night. “My heart just breaks for his wife Ruby and their children. Please keep them in your prayers. What an incredible legacy he leaves behind.”

Wrote John Ford Coley, “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 added, referring to the Seals & Crofts hit “We May Never Pass This Way (Again)”. Coley was a member of another hit duo of the era, England Dan And John Ford Coley, with Jim Seals’ younger brother, the late Dan Seals.

“You and Dan finally get reunited again,” Coley wrote. “Tell him and your sweet momma hi for me.”

With Jim Seals as the primary lead vocalist of the harmonizing duo, Seals & Crofts came to be the very emblem of “soft rock” with a run of hits that lasted for only about six years. Although none of the pair’s hits ever reached #1 on the Hot 100, their biggest songs were for a time as ubiquitous as any that did top the chart. “Summer Breeze” in 1972 and “Diamond Girl” in 1973 both reached #6, as did a more upbeat song in 1976, “Get Closer,” sung with Carolyn Willis.

Besides those three songs that reached the Top 10 on the Hot 100, four more made it to the adult contemporary chart’s top 10: “We May Never Pass This Way (Again)” in ’73, “I’ll Play for You” in ’75, “Goodbye Old Buddies” in ’77 and “You’re The Love” in ’78.