Meet Me on Cassiopeia.

Composer John Berger is plagued by marital problems and struggling with a deadline for the music for an operetta. When he is visited by the muse of music, Polyhymnia, the melodies begin to flow, but she also causes a lot of complications in his earthly life. Like John's wife Irene, she falls in love with flight lieutenant Harry, while her father Zeus looks on disapprovingly and decides to intervene. Meanwhile, the premiere of the operetta is fast approaching.