George Martin, often referred to as the “Fifth Beatle” and the band’s longtime producer, passed away. He was 90.

Drummer Ringo Starr broke the news on Twitter, adding, “God bless George Martin, peace and love to Judy and his family.”

Martin’s involvement with the Beatles ranged from producer to arranger to musician, as he produced nearly all of their songs along with being credited for adding strings to songs like “Yesterday” and “Eleanor Rigby.” Martin also played piano on “In My Life” and composed the orchestral section for “A Day in the Life.”

Paul McCartney posted a lengthy tribute on his Facebook saying, “The world has lost a truly great man who left an indelible mark on my soul and the history of British music.” He added, “I am proud to have known such a fine gentleman with such a keen sense of humour, who had the ability to poke fun at himself. Even when he was Knighted by the Queen there was never the slightest trace of snobbery about him.”

“RIP to my musical brother George Martin,” famed producer Quincy Jones wrote on Twitter. “We were friends since 1964 and I’m so thankful for that gift.”

British Prime Minister David Cameron also chimed in, adding, “Sir George Martin was a giant of music, working with the Fan Four to create the world’s most enduring pop music.”