Judy Holliday re-creates her Broadway role of flibbertigibbet telephone operator Ella Peterson in Bells are Ringing. Ella works for Susanswerphone, a hole-in-the-wall answering service run by her cousin Sue (Jean Stapleton).
Our girl Ella can't help but become involved in the lives of her customers, which brings her to the attention of a dimwitted police detective, Barnes (Dort Clark), who suspects that Susanswerphone is a front for a house of ill repute.
The cop is so obtuse that he never notices the story's genuine criminal, a flamboyant German bookie (Eddie Foy Jr.) who poses as a record executive and uses the names of composers as code for the various racetracks around the country.
To avoid Barnes' wiretapping, Ella goes around New York in person to minister to the needs of her clients--most notably playwright Jeffrey Moss (Dean Martin), who is in danger of becoming an alcoholic if he can't come up with a good idea for a play.
Assuming a false identity, Ella prattles on about some of her other clients, notably a dentist (Bernie West) who composes pop songs on his air hose. Moss is inspired by Ella, and eventually falls in love with her. Because she will not reveal who she really is to Jeffrey, Ella decides that her relationship is founded on lies, and walks out of his life.
But Moss, together with the other Susanswerphone customers who have been rescued by Ella, show up at Ella's doorstep for a happy ending.
Bells are Ringing is not an example of MGM's Arthur Freed unit at its best, but Judy Holliday is luminescent in this, her last screen role (incidentally, Holliday's blind date in one scene is played by her then boyfriend, jazz musician Gerry Mulligan).
The film's songs, by Betty Comden, Adolph Green and Jule Styne, include the hit numbers Just in Time and The Party's Over.