Song in the end credits of "That's Entertainment".

I have been looking for the title of one of the songs played in the end credits of "That's Entertainment" for years. I heard it on TCM this month and again in the 1978 movie "Death on the Nile". It played in the early part of the movie while Lois Chiles and Simon MacCorkindale danced in the ballroom while the entire cast members looked on from the upper level of the ballroom in "Death on the Nile". I'm sure it's a 1930s song. Would be grateful for any help.
Thank you !
BD

manhattan777, January 23, 2008; 7:46 PM