Steve McQueen, Cary Grant, David Niven, James Garner.
Think about the beginning of the "Dean Martin Show."
Dean in a prone / laying down, position on top of the piano.
Now, what is the first thing any singing coach will say, "You need to be standing erect manner," in order to sing.
Not good old Dino, he just belted them songs out like it was a nothing-burger.
That's what you call natural talent, and did Dino ever have IT!!!!!