George Martin who was often referred to as the "Fifth Beatle" has died. He was 90.
Martin was the group's record producer and collaborator, and served as a mentor to John Lennon, Paul McCartney, George Harrison and Ringo Starr.
Martin's death was confirmed by Adam Sharp, his manager in the United Kingdom.
He signed The Beatles in 1962 and, with the band, helped revolutionize the art of popular music recording.