Melody in May is a 1936 American short film starring singer Ruth Etting directed by Ben Holmes.
The movie opens with Ruth Etting (as herself) recording "St. Louis Blues", after which she declares that she is taking a month off, and going to where no-one can find her.
Over her ice cream, Ruth overhears Tommy's fellow students remarking on his social awkwardness.
However, Chuck is expected to be out of town that night, so as Mary leaves, she asks Tommy to take her, and he ecstatically agrees.
To rescue the situation, Ruth sings "It Had to Be You", accompanied by the excellent live band (which happens to be playing there for reasons not explained).