From Wikipedia:

I started out to become a jazz pianist; in the meantime I started singing and I sang the way I felt and that’s just the way it came out.
— Nat ‘King’ Cole, Voice of America interview

Few remember Nat ‘King’ Cole’s incredible piano playing abilities, but they certainly never seem to forget a his smooth, baritone voice, which handled languages outside of his native English with ease.

NPR dedicates a radio program to one of the smoothest voices jazz ever produced here.