George Harvey is a composer living in early 20th-century London, who is under immense stress due to the completion of his piano concerto. However, whenever he hears dissonances, he experiences blackouts. After one such episode, he finds himself in a different part of the town, where he reads about a murder in a newspaper.
Upon learning that someone in his neighborhood was murdered, George seeks help from Scotland Yard's doctor. The doctor assures him that there's nothing to worry about and recommends reducing his workload to relax like other people.
During a performance at a cheap musical, George meets Netta, a talented singer. Her passion for music inspires him to create a new motive for his concerto. However, Netta discovers that this motive could also be used as a song for her. The song sells well, and Netta becomes a frequent visitor to George's home, hoping to get more songs out of him.
George believes that Netta is in love with him and begins an argument with his girlfriend, Barbara, the daughter of Lord Henry. She wants the concerto as a souvenir for her father. George experiences another blackout, but this time, he wakes up in a different place entirely.
In this new location, George encounters a mysterious figure named "The Man" who seems to have knowledge about the concerto's origins. The Man tells George that he has been sent by a higher power to help him complete the composition, but only if he follows certain instructions.
George agrees to the terms and returns home, where he finds Netta waiting. They discuss the situation and decide to work together to finish the concerto. Together, they uncover the true purpose of the blackouts and the connection between the concerto and a powerful ancient symbol.
With the help of The Man, George finally completes the composition, which brings peace and harmony to both him and Netta. They share their success with the world, and George's music becomes a beloved classic, inspiring generations to come.