That was a big hit song made by Mack Gordon and Harry Warren in 1941 and performed by the Glenn Miller Band. Carmen and her band were short of Brazilian songs in Hollywood. Then her band leader Aloysio Oliveira from the Bando da Lua made an in-Portuguese version of the song and Mack Gordon only approved the inclusion of it in the movie because it would remind everyone of his original song due to its title & rhythm within that were kept.