VIDEO : Paul McCartney on George Martin's Death: 'The World Has Lost a Truly Great Man'

Paul McCartney has penned a moving tribute to the Beatles' producer George Martin, who died Tuesday at the age of 90. Below a photo of McCartney and Martin together in the studio on McCartney's official site, the singer wrote of his longtime producer, "The world has lost a truly great man who left an indelible mark on my soul and the history of British music." Why Beatles' Shea Show Was Even Greater Than You Knew " "I'm so sad to hear the news of the passing of dear George Martin.