Which opera  Pelléas et Mélisande and Die schweigsame Frau has fewer acts ?
Pelléas et Mélisande (opera) Pelléas et Mélisande ("Pelléas and Mélisande") is an opera in five acts with music by Claude Debussy. The French libretto was adapted from Maurice Maeterlinck's Symbolist play "Pelléas et Mélisande". It premiered at the Opéra-Comique in Paris on 30 April 1902 with Jean Périer as Pelléas and Mary Garden as Mélisande in a performance conducted by André Messager, who was instrumental in getting the Opéra-Comique to stage the work. The only opera Debussy ever completed, it is considered a landmark in 20th-century music.
Daphnis et Alcimadure Daphnis et Alcimadure (in Occitan classical norm, Dafnís e Alcimadura, or according to the original libretto spelling, Daphnis e Alcimaduro) is an opera by the Baroque violinist, conductor and composer Jean-Joseph Cassanéa de Mondonville to a libretto in the Occitan language, written by the composer himself and loosely inspired by La Fontaine's fable bearing the same title. It takes the form of a pastorale in three acts and was later endowed with a prologue in French entitled "Les jeux floraux", to a libretto by Claude-Henri de Fusée de Voisenon.