Ivar Hallström was the leading opera composer in Sweden, indeed the creator of Swedish national opera. With Duke Magnus and the Mermaid, a romantic operetta in three acts (musical numbers separated by dialogues), Hallström and his librettist consciously created a work of national character. Set in Vadstena Castle, the story concerns a duke who thinks he hears a mermaid’s call and throws himself in the water. The composer assigns different musical styles to each character drawing on old-fashioned ballad, virtuosic popular and dance songs, grand Italian romantic opera and authentic folk-style.