Ah, what could have been. Paul McCartney was the only member of the Beatles who, after the split-up, was able to do a solo album, completely on his own, without any supporting musicians. His solo debut, 1970's McCartney, featured Paul on all the instruments: guitars, bass, keyboards and drums. But in this interview, George Harrison recalls that Paul started out playing the trumpet, possibly because his father had played in a jazz band.

But Paul, it seems, always had his eye on stardom. And while Louis Armstrong and Dizzy Gillespie were stars in their own right, that would not be Paul's path. He was also a huge fan of Elvis Presley, Little Richard and Buddy Holly, and wouldn't be satisfied with playing his instrument or singing, he wanted to do both at the same time. And so, he picked up the guitar, and later the bass, the piano and the drums.

These days at his concerts, Paul switches between bass, electric and acoustic guitar and electric and grand piano (his drumming is usually limited to studio sessions when he plays at all). But imagine what the Beatles would have sounded like with McCartney playing trumpet instead of bass.