Radio engineer Lloyd Nolan meets nightclub singer Ann Southern, and tells her he can get her a tryout at the station he works for. At first she doesn't believe him, and then Nolan gets into a beef with pompous, incompetent station manager Berton Churchill and pops him one, which gets him fired and her tryout cancelled. Meanwhile, Douglas Dumbrille, who runs the nightclub Miss Southern sings at, gets a bright idea. His gang of crooks have been using a radio transmitter to jam police wavelengths, which keeps them from being pursued. Why not pretend he's actually Nolan and blackmail Churchill by threatening to block his broadcasts.
Nolan, as usual, offers a solid, unbelievable performance, and Miss Southern actually could sing; she had been performing with Artie Shaw's orchestra. The details of how Nolan sends word of where he's being kept by Dumbrille's hoods is sent out early, and everyone studiously ignores the obvious clue until the time arrives to end the movie. I also don't know what the title refers to.