3. Paul McCartney
Paul McCartney gets so much attention for his brilliant songwriting in The Beatles that his stunning bass playing abilities are often overlooked. But listen to any Beatles songs and focus on his deeply melodic, flawless bass parts. He took on the role reluctantly after original bassist Stuart Sutcliffe left the group and nobody else wanted to take over his instrument. He soon mastered it, but also proved adept at guitar and drums - as he proved when Ringo Starr briefly quit during the making of 1968's The White Album and Paul took his place behind the kit in the studio with great ease.