Detective Chief Inspector Tom Barnaby (John Nettles) can't help but notice that more people than ever before seem interested in the work of long-dead composer Joan Alder, who wrote the well-known song "Midsomer Rhapsody." First, Alder's former music teacher turns up dead, and an early draft of her most famous piece is found among his possessions. But the plot thickens when Alder's long-lost daughter, Sarah, comes back into town.