Peter Banks, the original guitarist for progressive-rock titans Yes, passed away last weekend. He was 65 years old. A press statement from Banks’ family said that the guitarist passed away in his sleep.

Banks co-founded Yes with Jon Anderson and Chris Squire in the late 1960s. Having played on the band’s first self-titled record and Time And A Word before being replaced by the more well-known Steve Howe in 1971, Banks laid the groundwork for what became the band’s signature sound in the 1970s. As such, many credit Peter Banks with being the creator of prog-rock guitar playing as a whole.

After leaving Yes, Banks recorded albums with his new band Flash as well as under his own name. For his work in both bands, Banks was often cited as one of the greatest guitarists of all time.

In an official statement released on Yes’s website, the band described Banks as “a huge piece of the fabric that made Yes what it is, and our thoughts and sincere condolences go out to his family.”