Jim Seals, half of US soft rock duo Seals and Crofts, has died aged 80.

Along with Darrell “Dash” Crofts, the Texan was best known for hits including Summer Breeze, Diamond Girl and Get Closer.

His death was announced by friends and family on Tuesday, who described him as a “musical genius” and a “contemplative man”.

Seals and Crofts formed in the late 1960s, with the two men having known each other as teenagers, and were among a wave of soft-rock groups that included Hall and Oates, America, Bread as well as England Dan and John Ford Coley.

They disbanded in 1980 but reunited in 1991 and then again in 2004 to release their final album Traces.

Writing on social media, Seals’ cousin Brady Seals praised the “incredible legacy” the musician left behind.

“I just learned that James ‘Jimmy’ Seals has passed,” he wrote.

“My heart just breaks for his wife Ruby and their children. Please keep them in your prayers.

“What an incredible legacy he leaves behind.”

Coley also posted a lengthy tribute to Seals in which he recalled times spent together.

“Wow. Don’t even know where to begin… I spent a large portion of my musical life with this man,” he said.

“We didn’t always see eye-to-eye, especially as musicians, but we always got along and I thought he was a bona fide, dyed-in-the-wool musical genius and a very deep and contemplative man.

“He belonged to a group that was one of a kind.

“I am very sad over this but I have some of the best memories of all of us together. Rest In Peace Jimmy.”