Which opera  Pelléas et Mélisande and Die schweigsame Frau has fewer acts ?
Die schweigsame Frau Die schweigsame Frau ("The Silent Woman"), Op. 80, is a 1935 opera in three acts by Richard Strauss with libretto by Stefan Zweig after Ben Jonson's "Epicoene, or the Silent Woman".
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.