Abstract : The opera "King and Marchal" by Peter Heise belongs to the Danish cultural canon. But when the opera was first performed in 1878 critics were reluctant to appreciate its qualities. The revengeful murder of King Erik Glipping in Finderup Barn in 1286 was not justified if the marchal's wife had willingly been seduced by the king as claimed by the composer and his librettist. Neither did the opera seem to propagate a political motive for the murder. The article points to the possibility of understanding the opera as a contribution to the lively debate on women's emancipation and sexuality in the decades around 1870. However, when the opera was elected to form part of the official Danish cultural canon in 2006 it was praised for its "wonderful amalgamation of lyrics, music and drama". The judgement illustrates that we no longer expect a musical drama from the past to have possessed critical potential or we do not necessarily grasp the inherent values.