5 guys who've been called the 'fifth Beatle'

In 1962, George Martin listened to the band's demo tape and, while he wasn't convinced about the quality of their performance, he liked their charisma. Martin offered the foursome a record deal and the rest is history. He produced almost all of The Beatles' records, which won him six Grammys. Until his death in March 2016, he was considered one of Britain's greatest music producers.

He played drums with The Beatles for two years before he was thrown out of the band, never to have contact with them again. After the initial shock, Pete Best built a quiet, normal life for himself. He initially took a break from music, but came back in 1988 with a band of his own. "The Pete Best Band" still tours actively around the world.

In the early years, John Lennon's college friend played bass with The Beatles. In Hamburg, he fell in love with German artist Astrid Kirchherr, who photographed the band during their concerts. She was the one who convinced them to try their iconic bowl cuts. In 1961, Sutcliffe stayed in Hamburg to be with Kirchherr, but he tragically died a year later due to a cerebral hemorrhage.

In 1960, the graphic designer and illustrator met The Beatles in Hamburg. Since then, he's been a longtime friend and partner of the band. He designed a number of their record covers, including their "Revolver" album, in which he can be seen on the right side of the collage. In 1967, he won a Grammy for his design.

Paul McCartney himself is said to have dubbed Brian Epstein the "fifth Beatle." As the band's manager, Epstein had the guys wear suits and ties, defined their look, and organized TV appearances and world tours. In 1967, he died at the age of just 32 of an overdose of pills and alcohol. His death marked the beginning of the end of The Beatles, who broke up three years later.