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.
Romeo und Julie Romeo und Julie is a singspiel in three acts by composer Georg Benda. The opera has a German libretto by Friedrich Wilhelm Gotter that is based upon Christian Felix Weiße's translation of William Shakespeare's play "Romeo and Juliet".