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".
Teseo Teseo ("Theseus", HWV 9; ] ) is an opera seria with music by George Frideric Handel, the only Handel opera that is in five acts. The Italian-language libretto was by Nicola Francesco Haym, after Philippe Quinault's "Thésée". It was Handel's third London opera, intended to follow the success of "Rinaldo" after the unpopular "Il pastor fido".