The Telephone, or L'Amour a trois is an opera buffa in one act by Gian Carlo Menotti, most famous I suppose for his Christmas opera written for television Amahl and the Night Visitors.

The Telephone is a very short opera (about 26 minutes) that was originally produced on February 18, 1947 and had three performances for The Ballet Society at the Heckscher Theater at Fifth Avenue and 104th Street in New York City, which is now home to El Museo del Barrio.

This original presentation was a companion piece to his full-length opera The Medium and the cast was as follows:
Lucy - Marilyn Cotlow
Ben - Paul Kwartin
Conductor(s) - Leon Barzin - Emanuel Balaban
Set and Costume Design - Horance Armistead

The entire production moved to the Ethel Barrymore Theater on Broadway and opened on May 1, 1947. It was produced by The Ballet Society, Chandler Cowles and Efrem Zimbalist, Jr, in association with Edith Lutyens. The only change from the original presentation was the role of Ben, being taken over by Frank Rogier. Emanuel Balaban remained the conductor.

The synopsis of The Telephone is simple:
Ben is alone with his girl Lucy, who has just received an exquisite gift from him. Ben tells Lucy that he is going away soon and that his train leaves in a hour, so there is something very important he wants to tell her. Just as he is about to, the telephone rings, it is her friend Margaret. Margaret endeavors to invite Lucy out that night, but she feigns sickness and begs off. After some interminable gossip, she finally goes off the line and sends her attention back to Ben.

Ben tentatively begins again, struggling with the words he wants to use, when the telephone rings again. This time it is a wrong number, which makes Lucy bristle. Ben reminds Lucy that time is getting short and that he must hurry. Lucy has a brilliant idea and calls for the correct time so that Ben can more properly gauge his schedule. He thanks her and undaunted, he begins again, as luck would have it though, the telephone rings yet again! This time it is her friend George, who apparently is very agitated about something Lucy has said or done and proceeds to berate her stingingly (or at least that's the impression we get, for we always only hear Lucy's side of the conversation.) The argument becomes extremely heated and George hangs up on Lucy. Lucy begins to cry. Ben endeavors to calm her down, but Lucy runs out of the room to get a handkerchief.

Left alone with this nemesis, Ben sings about this "other man" he must contend with, the telephone. He spots a pair of scissors on the table near the phone and creeps up menacingly towards the telephone. As if a child, crying desperately for help, the telephone rings loudly, sending Lucy rushing in to pick it up into her arms lovingly and scold Ben for attacking it.

Ben makes one final attempt to get Lucy's attention, but she insists she must call her friend Pamela and explain the situation with George before anyone else gets hold of her. She promises Ben it won't be very long and makes her call. Ben realizes he must go or he will miss his train. He leaves Lucy as she is in the middle of her call.

When Lucy hangs up, she realizes that Ben has left her alone "with her telephone." She wonders what he wanted to tell her that was so important. She starts to feel dejected and depressed when the telephone rings. It is Ben. He has found the only way to get her undivided attention, using the "If you can't beat 'em, join 'em" approach. He is calling her from a telephone booth in the train station. Now he gets the chance to ask her what he's been trying to this whole time.

"Will you Marry Me?"

Lucy accepts and they sing a duet of their love for one another and the marvelous invention of the telephone that will keep them close to one another despite their physical distance. Lucy promises to wait for him but begs him not to forget one thing.

"Your eyes? Your hands? Your lips?"
"No"
"My Number"

They promise to speak on the phone every day and the curtain falls on the pair of lovers singing Lucy's telephone number.