Chris Squire, the bass guitarist and co-founder of 1970s British progressive rock band Yes, has died at the age of 67.
Current Yes keyboardist Geoff Downes first tweeted the news, writing: "Utterly devastated beyond words to have to report the sad news of the passing of my dear friend, bandmate and inspiration Chris Squire."
His band mates today confirmed his death on the group's Faceboook page.
In a statement, they said: "It's with the heaviest of hearts and unbearable sadness that we must inform you of the passing of our dear friend and Yes co-founder, Chris Squire.
"Chris peacefully passed away last night in Phoenix Arizona, in the arms of his loving wife Scotty."
Squire, who was the only member of the group to feature on every studio album, revealed just a month ago he was suffering from a rare form of leukaemia.
The statement described Squire as the band's "linchpin" and the "glue" that held it together.
It said: "For the entirety of Yes' existence, Chris was the band's linchpin and, in so many ways, the glue that held it together over all these years. Because of his phenomenal bass-playing prowess, Chris influenced countless bassists around the world, including many of today's well-known artists.
"Chris was also a fantastic songwriter, having written and co-written much of Yes' most endearing music, as well as his solo album, Fish Out of Water.
"Outside of Yes, Chris was a loving husband to Scotty and father to Carmen, Chandrika, Camille, Cameron, and Xilan. With his gentle, easy-going nature, Chris was a great friend of many … including each of us. But he wasn't merely our friend: he was also part of our family and we shall forever love and miss him."
Squire was born in Kingsbury, in northwest London. His father was a cab driver, and his mother a housewife. He sang in the choir of Haberdashers' Aske's Boys' School, but was suspended in 1964 for having his hair too long.
Yes were formed in 1968 when singer Jon Anderson met self-taught bassist Squire in London. Their big break came a year later when they signed to Atlantic Records after opening for Janis Joplin at London's Royal Albert Hall.
Their debut single, Sweetness, and first album, Yes, were released later that year.
Other albums included 1971's Fragile, 1972's Close To The Edge and 1977's Going For The One. In 1983 they released 90125, which featured the No 1 hit single Owner Of A Lonely Heart. Squire also released a solo album, Fish Out Of Water, in 1975.
The group's most recent studio album, Heaven & Earth, came out last year. They attracted a large following with their mixture of mystical lyrics, rambunctious harmonies and the powerful falsetto of lead vocalist Jon Anderson.
In May, Squire revealed that he had been recently diagnosed with acute erythroid leukemia, which would force him to miss the band's summer co-headlining tour with Toto.
People took to Twitter to pay tribute to him with comedian and novelist David Baddiel tweeting: "Ah..Chris Squire, gone to the great Roundabout in the sky."
Former Metallica lead guitarist Dave Mustaine, who co-founded Megadeath tweeted: "A tremendous talent and a terribly sad loss. Prayers to Chris Squire's family and band."