"Yes Sir, That's My Baby" is an American song written in 1925 by Walter Donaldson and Gus Kahn. Recorded by more than 100 artists, it was a hit for Eddie Cantor, Rick Nelson and Ol' Blue Eyes.
My favorite version is here, performed by Jason Robards (and Barry Gordon) in the movie-based-on-Herb Gardner's-play A Thousand Clowns. It's a little messed up - snipped together from parts in the film where Robards stops singing and we cut away to talking scenes. So it's not like a flow-y, play-at-a party song, but it has something going for it - "a genuine sort of meaningful bustedness" - that is mostly impossible to find in a neat, slick album recording.
A Thousand Clowns is about a nonconforming crazy guy played by Robards who's been out of work for awhile and takes pleasure in all sorts of eccentric fun. He can be pretty annoying but he's definitely my kind of guy. The catch is that he takes care of his 11-year-old nephew and social services is on their ass to step up their living conditions and start acting like normal citizens. Robards needs a job.