Which opera, if any,  Venus and Adonis or Bluebeard's Castle has more acts ?
Bluebeard's Castle Bluebeard's Castle (Hungarian: A kékszakállú herceg vára ; literally: "The Blue-Bearded Duke's Castle") is a one-act opera by Hungarian composer Béla Bartók. The libretto was written by Béla Balázs, a poet and friend of the composer, and is written in Hungarian, based on the French literary tale "La Barbe bleue" by Charles Perrault. The opera lasts only a little over an hour and there are only two singing characters onstage: Bluebeard ("Kékszakállú "), and his new wife Judith ("Judit " ); the two have just eloped and Judith is coming home to Bluebeard's castle for the first time.
Der Waffenschmied Der Waffenschmied (The Armourer) is an opera (Singspiel) in three acts by Albert Lortzing. The German-language libretto was by the composer after Friedrich Wilheim von Ziegler's "Liebhaber und Nebenbuhler in einer Person" (Lover and Rival in One Person). This is often considered his third most popular work. His works are considered to be part of the Biedermeier period. It premiered in Vienna at the Theater an der Wien on 31 May 1846 conducted by Lortzing. The role of Marie was written with Jenny Lind in mind who he hoped would sing the part. The opera was eventually successful enough that Lortzing was offered the post of Kapellmeister at the theatre which he held until the revolution of 1848, when he had to return to Leipzig. Arnold Schönberg, arranged Lortzing’s "Waffenschmied“ for piano for 4 hands. The story is set in the city of Worms in the 16th century.