Veteran record producer George Martin, best known for honing The Beatles sound as they rose to global renown, died on Tuesday (March 8). The 90-year-old passed away at his home, the BBC reports.

Many fans first learned the news from ex-Beatles drummer Ringo Starr, who shared the news on Twitter that evening. Martin was responsible for producing dozens of Beatles hits, from "Love Me Do" to "I Am the Walrus." He's also the man behind many iconic sounds on the band's records, including the harpsichord on Sgt. Pepper's "Fixing a Hole," and he arranged the score for the band's film Yellow Submarine.

Paul McCartney shared a longer message honoring his former colleague on his website.

"I’m so sad to hear the news of the passing of dear George Martin," McCartney began. "I have so many wonderful memories of this great man that will be with me forever. He was a true gentleman and like a second father to me. He guided the career of The Beatles with such skill and good humour that he became a true friend to me and my family.

"If anyone earned the title of the fifth Beatle it was George. From the day that he gave The Beatles our first recording contract, to the last time I saw him, he was the most generous, intelligent and musical person I’ve ever had the pleasure to know." He goes on to describe one of Martin's highly influential moments on The Beatles' sound, when he persuaded a reluctant McCartney to add a string quartet to "Yesterday."

"His idea obviously worked because the song subsequently became one of the most recorded songs ever with versions by Frank Sinatra, Elvis Presley, Ray Charles, Marvin Gaye and thousands more," McCartney writes.

Celebrities including JK Rowling, Jon Cryer, singer Roseanne Cash and more expressed their condolences on social media. "; visionary groundbreaking producer and sonic architect of the Beatles' recorded work," guitarist Tom Morello tweeted.

Scroll down to see more celebrity reactions to Martin's life and death, and to listen to our playlist of 20 George Martin-produced tracks, including "Goldfinger," Shirley Bassey's bombastic theme for the 1964 James Bond film of the same name.

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