What form of entertainment are Martha and Königskinder both performed?
Martha (opera): Martha, oder Der Markt zu Richmond ("Martha, or The Market at Richmond") is a "romantic comic" opera in four acts by Friedrich von Flotow set to a German libretto by Friedrich Wilhelm Riese and based on a story by Jules-Henri Vernoy de Saint-Georges. Königskinder: Königskinder (German for "The King's Children") is a stage work by Engelbert Humperdinck that exists in two versions: as a melodrama and as an opera or more precisely a "Märchenoper".
opera