Classic rock fans were left mourning this weekend when American music legend John Regan passed away at the age of 71. According to Fox News, Regan died on Friday and the cause of his death remains unknown. 

The network noted that Regan had a long career playing as a bassist alongside such stars as Peter Frampton, David Bowie and Mick Jagger.

Peter Frampton: "John Regan was the best of us."

Frampton reacted to news of Regan's death with a series of tweets, saying, "There might only be a handful, if that, of people who come into your world and truly enrich your life. I have lost one of my closest buddies."

The British-born rock star recalled how Regan "certainly enriched my life because of the person and the great player he was," adding that "John Regan was the best of us."

There might only be a handful, if that, of people who come into your world and truly enrich your life. I have lost one of my closest buddies. He certainly enriched my life because of the person and the great player he was. John Regan was the best of us. He went out of his way pic.twitter.com/IEZ1Vi4CoR

— Peter Frampton (@peterframpton) April 8, 2023

"He went out of his way to help people when things weren’t right. It didn’t matter who you were, prince or pauper," Frampton in a subsequent tweet.

Former Kiss member calls Regan a "wonderful person"

"I know there are many of you out there who knew him. He was a friend to all. Always musically inspiring and one of the funniest people on the planet," Frampton said of Regan.

"My thoughts are with his wife Cathy, his children, Christopher and Jeness and his grandchildren. I love you my brother you will be missed by so many," Frampton concluded.

Frampton was not alone in expressing sadness over Regan's death, as former Kiss member Bruce Kulick praised him for being "a fantastic musician and wonderful person."

Sad news about the loss of bassist John Regan today. We got to tour together in Australia in 2017. He was a fantastic musician and wonderful person. (John in in red next to me at head of the table) RIP John @FourByFate pic.twitter.com/xfKKugs7rW

— Bruce Kulick (@brucekulick) April 7, 2023

Regan honored by venue in New York state

Fox News noted that Regan performed for decades at The Chance Theater in Poughkeepsie, New York and the venue put up a Facebook post regarding his death.

"We are sad to announce the passing of one of our Chance family, John Regan," the post declared on Friday.

"John was an incredible musician, a rockstar, but most of all, he was one of the nicest, most humble humans you’ve ever known. John, you will be missed by all of us who had the honor of knowing you. RIP," it said.