Norman Truscott works as a dry cleaner, but dreams of being a famous singer. He is awestruck when his idol, the singer Vernon Carew, brings his suit into the shop to be cleaned. Carew gives Norman free tickets to his show.

Norman's girlfriend, Judy, cannot walk. He pushes her, in her wheelchair, to Miss Dymphna Dobson's music school, where she works as an accompanist, and where he takes singing and elocution lessons.

Later, at the theatre, Norman watches as Carew's performance is badly received. Norman remonstrates with hecklers in the audience, but they throw ice cream at him. Attempting to win over the audience, Norman sings along with Carew. But Norman's performance is more popular than Carew's.

Realising the quality of his singing, Carew and his agent, Harold Franklin, decide to use Norman's voice to revitalise Carew's flagging career, without Norman's knowledge. Norman and Judy are invited to Carew's flat, where Norman sings, accompanied on the piano by Judy. Carew and Franklin secretly record his singing. Carew offers Norman further lessons, provided that he moves into his flat and serves as his private secretary. Judy is upset, but encourages Norman in his ambition.

Franklin takes the recording of Norman to a record company, claiming that the performance is by Carew. The record company is impressed and requests further material. Franklin and Carew attempt to surreptitiously record Norman once more, but without Judy's accompaniment, he is too lacking in confidence to sing.

Eventually, Carew manages to record Norman as he sings in the bath. Record company executives enthuse over what they are told is Carew's latest performance. Carew appears on television, miming the words of the song. Miss Dobson recognises Norman's voice, but Norman does not believe that it is his.

Norman is forced to work as a waiter at a party held by Carew. Miss Dobson forces her way in, determined to expose Carew's deception. But when Norman is asked to sing, to prove her claims, he is too nervous to do so and is humiliated.

Worried about his lack of self-belief, Miss Dobson sends Norman to see a psychiatrist, who hypnotises Norman. In a trance, Norman becomes highly self-confident. The psychiatrist takes Norman to an exclusive club; Norman impresses the members with his bravado. But later, when the psychiatrist snaps his fingers, his new confidence disappears.

Carew is booked to appear at the London Palladium. Miss Dobson bursts into his dressing room and forces him to confess his deception, but Norman is still not entirely convinced. She knocks Carew out. Norman, dressed in Carew's clothes, is sent out on stage in Carew's place.

Franklin and the stage hands attempt to stop Norman from singing. Finally, Carew confronts Norman and sends him off stage. Carew pretends to sing, miming to a recording of Norman's voice playing off stage. Attempting to switch off the record, Norman accidentally speeds it up and Carew's deception is at last revealed.

Finally confident, Norman sings his song on stage as Judy watches from the wings. His performance is enthusiastically received. As crowds of well-wishers gather around Norman, Judy sadly wheels herself away. However, Norman turns his back on the crowds and, happily reunited with Judy, they head for the exit.