Duetto takes place in 1965 and tells the story of Cora, 18, a young Brazilian from an Italian family, who, after losing her dad in a tragic car accident, goes with Lucia, her grandmother, to Italy, in the region of Puglia, where her old family home still stands. Lucia, aiming to sell an old family land lot, reencounters, along with her granddaughter; her sister, Sofia, and her husband Gino, with whom she hasn't talked with in 40 years. Things get complicated when the sale of the land turns out to be lost in bureaucracy and takes more time than what was expected, due to the upcoming traditional Music Festival of the town, where the biggest Italian musicians of the time performed. Lucia and Cora end up being forced to extend their stay and old family issues are revealed, creating for Cora an intense journey of grief and growth, along with the unexpected, almost fantastical, encounter between the girl and Marcelo Bianchini, Italian "cantautore" and an idol of her deceased father.