Leonel is a pianist, nostalgic of sweet melodies, while his son is the (real-life) leader of Os Gatos Pretos (black cats), a twist musical group. The conflict is eventu ally solved when Leonel's daughter, Cilinha, starts dating Raúl, a well-off young man, who promote a new dancing club, the Lisboa Antiga e Moderna, where old new music get even shares.
