Soon after a young woman breaks off her engagement to a doctor, the doctor is found murdered. Suspicion falls on his ex-fiancé and a pilot with a checkered past.

A young Irishwoman comes to the United States to live and work with her mother as a cleaning lady at Carnegie Hall. She becomes attached to the place as the people she meets there gradually shape her life. The film also includes a variety of performances from some of the foremost musical artists of the times: conductors Bruno Walter & Leopold Stokowski, solists Arthur Rubinstein & Jascha Haifetz, singers Lily Pons & Jan Peerce and bandleader Vaughn Monroe among many others.

A lawyer who is planning to run for District Attorney accidentally kills a gangster who owns the nightclub where the attorney's girlfriend is a singer. Although he manages to cover up his involvement in the crime, his girlfriend discovers the body and is subsequently charged with the murder.

Imprisoned during the Spanish Civil War, John "Kit" McKittrick is released when a New York City policeman pulls some strings. Upon returning to America, McKittrick hears that a friend has committed suicide, and he begins to smell a rat. During his investigation, McKittrick questions three beautiful women, one of whom has a tie to his refugee past. Pursued by Nazi operatives, McKittrick learns of the death of another friend, and begins to suspect the dark Dr. Skaas.

Ole Olsen and Chic Johnson are Broadway stars who return to Universal Studios to make another movie. The mere mention of Olsen and Johnson's names evacuates the studio and terrorizes the management and personnel. Undaunted, the comedians hire an assistant director and unknown talent, and set out to make their own movie.