Ray Thomas, a founding member of The Moody Blues whose flute playing was key to its lush orchestral sound, died Thursday at his home in Surrey, England. He had turned 77 a week earlier.

Thomas, who had suffered from prostate cancer since 2013 and had retired the Moody Blues in 2002 during to mobility issues, was scheduled to be inducted into the Rock and Roll Hall of Fame in April.

Thomas and Mike Pinder formed the Moody Blues with Denny Laine, Graeme Edge and Clint Warwick in Birmingham in 1963. They signed with Decca Records and had a global hit with a cover of Bessie Banks’ “Go Now” in 1965.

Justin Hayward and John Lodge replaced Laine and Warwick in late 1966 and a year later, they unveiled a new sound on the album Days of Future Passed, which heavily featured the Mellotron, cellos and Thomas’ flute playing and was one of the first albums to be labeled prog-rock. The album, which would yield the hit single “Nights in White Satin” and go to #3 five years after its release, introduced Thomas as songwriter as well; he penned “Another Morning” and “Twilight Time.” Among his later compositions for the band were the psychedelic staple “Legend of a Mind” plus “Dear Diary,” “For My Lady” and “Veteran Cosmic Rocker.”

Besides providing harmony vocals, Thomas also played piccolo, harmonica and saxophone on Moody Blues records.

After the band went on a three-year hiatus in 1974, Thomas released two solo albums, From Mighty Oaks (1975) and Hopes Wishes and Dreams (1976). In 1977, he was part of the re-formed group though as the band developed a synth-heavy sound for the MTV era, his contributions declined. He last recorded with the Moodys on 1991’s Keys of the Kingdom.