Marsh Music is set along the Gulf of Mexico Coast, in Cameron Parish, Louisiana. It's a quiet spot, with many Cajun people of Acadian heritage-living in this rather isolated marshland. There's always excitement there, especially in the vast marshes and swamps that are home to alligators, moccasins, nutria, birds and waterfowl. They each have their own voice and together they make The Music of the Marsh.

Sheriff Suzette Benoit is a much-respected public figure, but someone is out to get her. They don't want her to find Pierre Babineaux's killer and be led to a gunrunning operation using shrimp boats.

Always nearby are three old men, jokingly called The Holy Trio, who manage to get involved in Suzette's cases, even though she repeatedly warns them to bug out. The Holy Trio includes Grandpere, Suzette's grandfather, Father John, their beloved neighbor, and Louie, the church custodian, who is never seen without his trusty trumpet.

When The Holy Trio finds out that their close friend, Pierre Babineaux is missing they get restless. When they find out that his body is hanging on a cypress stump, they get involved.

This novel is strictly fiction, although some events and names of the little towns are true