Anna, Bett, and Carrie Quinlan were childhood singing stars, The Alphabet Sisters. As adults they haven't spoken for years, ever since Bett's fiance left her for another sister. Now Lola, their larger-than-life grandmother, summons them home for her 80th birthday extravaganza and a surprise announcement she wants them to revive their singing careers and stage a musical she has written. Rehearsals get underway, and family secrets begin to be shared and revealed. But just as the rifts begin to close, The Alphabet Sisters face a test they never imagined.