Mrs O'Brien is proud to run Ireland's oldest music shop, a landmark in the city of Dublin. But greedy property developers threaten the peace of her beloved West Stephen Street, buying up buildings and bullying tenants. They have money, and the support of corrupt local officials but the businesses decide to fight back. When a hated estate agent is found dead in the local café, the gardaí arrest the owner, Dan. Mrs. O'Brien is sure there's more to the story - and with the help of her protégé Michael, madcap teen Mai and the Super Ukers Ukulele group, she sets out to clear his name. But who can she trust and who is On the Fiddle? Based on the real life legendary Charles Byrne Music Shop, 1870-2021, and filled with a host of authentic Irish characters and fun, this is a cozy mystery for music lovers everywhere!