When You're in Love is a 1937 musical film starring Grace Moore, Cary Grant, and Thomas Mitchell. Moore sings "Minnie the Moocher" in one scene. She also sings the wonderful Ernesto Lecuono classic "Siboney" (though her Spanish is not perfection) drooled over by Cary Grant. The movie was directed by Robert Riskin. Louise Brooks was originally cast in the female lead; she very briefly appears as one of many ballet dancers in a musical sequence. Some of the songs were by Jerome Kern.