Chris Squire, the bassist and co-founder of prog-rock giants Yes, died today in Phoenix, Arizona, after battling a rare form of leukemia, according a post on the band’s official Facebook page. He was 67.

Born in Kingsbury, England, on March 4, 1948, Squire was suffering from acute erythroid leukemia. Last month, Yes revealed Squire’s diagnosis, adding that he would have to take a break from touring with the group and that former member Billy Sherwood (with whom Squire had recorded and performed) was stepping in for their co-headlining 2015 North American tour with Toto. This was to be the first time Squire would not be a part of the Yes live line-up.

Here’s the post from the Yes official FB page:

Best known for playing his Rickenbacker bass, Squire co-founded Yes in 1968 and the following year released their self-titled album with bassist Squire, singer Jon Anderson, guitarist Peter Banks, keyboardist Tony Kaye, and drummer Bill Bruford. Squire, one of Yes’s key songwriters, went on to appear on every one of the band’s 20-plus albums. His bass playing was a driving force in the group, with standouts being “Roundabout,” “Starship Trooper,” “”Long Distance Runaround”,” “Yours Is No Disgrace,” and even their wildly successful 1983 pop-hit “Owner of a Lonely Heart” from the album 90125. Just listen to his amazing solo tune “The Fish (Schindleria Praematurus)” from 1972’s Fragile and prepare to be blown away.

To say the music world has lost a legend today is an understatement. Not only was his songwriting contributions to rock music enormous — with the tracks like “I’ve Seen All Good People,” “Heart Of The Sunrise,” and one of my favorites “Perpetual Change,” — this man’s bass playing has influenced generations of rock fans the world over, and I count myself among them. To listen to the Yes records pre-90125 is to be magically transported to a more awesome place, no drugs necessary! “How does he do that?,” you will wonder, “How can his fingers fly like that?” I know that’s how I felt when I first heard Yes as a little girl and his playing is what, in part, prompted me to pick up the bass and want a Rickenbacker of my own (which I eventually got!). Yes has always been one of my favorite bands, and I’m glad that I got to see them live many times throughout the years, including on the mind-blowing “Union” tour in 1991 at NYC’s Madison Square Garden, which featured 8 of the band’s key members performing together in the round! I can listen to Yes, namely The Yes Album, Fragile, and the epic Tales from Topographic Oceans, repeatedly.

On a very personal note, Yes’s music has affected me in many important ways. Back in 2002, I was hospitalized with a mystery illness that basically had me on my deathbed until a miracle ear specialist diagnosed me with an extreme case of Cholesteatoma in my left ear. While in the hospital before my diagnosis as I felt like I was slowly slipping away and very unresponsive, my husband (also a huge Yes fan) put on Yes on his iPod and put the headphones near my right ear so I could hear it. Within seconds, I opened my eyes and “came back to life” so to speak. I’ll never forget that feeling, as it was the first time that I felt like I had a fighting chance (and thankfully I did, after several surgeries!). I am beyond saddened right now to know that the world no longer has Chris Squire in it and that fans, including myself, will never again get to see these rock legends perform with the extraordinary Chris Squire. But, he certainly left his mark on the world with his music.

Here’s the original announcement of Squire’s diagnosis:

Here’s the announcement of his death:

RIP Chris Squire
March 4, 1948 – June 28, 2015