At age nine, Yadra left Castro’s Cuba. Now, as Alzheimer’s sets in, her mind returns to that time and place, and her American-born daughter, Zelia, brings family secrets to light. With her wife, Zelia embarks on a journey to understand the love that led her mother’s beloved tia-abuela to stay behind—and to better understand herself. Spanning two countries and three generations, Azul fuses music and memory to ask: what is the true language of love?