With his impossibly smooth voice and debonair style, soulful crooner Nat "King" Cole began his career in the '30s as pianist in his own jazz trio. By the late '40s, he was a star, having crossed over to the pop world thanks to his lushly orchestrated ballads. In the '50s, Cole was one of the biggest pop singers in America, scoring No. 1 hits with standards like "Mona Lisa," "Nature Boy," and the indelible romantic ballad "Unforgettable." By the time of his 1965 death from lung cancer at the tragically young age of 45, Cole was one of the most beloved entertainers in the world.