The Music Room traces a pivotal year in the life of a fifty-two-year-old woman. Cath Breslin was only twenty when her mother died. In her grief, she buried her dream of becoming a writer, thinking it too frivolous, and became a nurse instead.

Now, thirty-two years later, happily married and the parent of a grown daughter, Cath feels something is missing. She had often wondered how her life would have turned out if her mother hadn't died. She imagined the books she might have written.

Cath enrolls in a memoir workshop to resurrect her dream. She writes about what she had lost and left behind after her mother's death. During the year, Cath uncovers buried parts of herself, realizing she has not fully mourned her mother's death, and discovers how her unresolved grief has affected her life and her relationship with her husband.

Cath's life changes in other unexpected ways during the year. She learns how easy it is to get drawn into another person's drama in a memoir class when she finds herself entangled in the life of a dangerous narcissist.