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.
Leben des Orest Leben des Orest ("The Life of Orestes") is a grand opera in five acts (eight scenes) with words and music both by Ernst Krenek. It is his Op. 60 and the first of his own libretti with an antique setting. The score is inscribed with the dates of composition: 8 August 1928 – 13 May 1929, and includes indications of recommended cuts made for the first production. It premiered at the Neues Theater in Leipzig on 19 January 1930, and opened at the Kroll Opera House in Berlin in early March of the same year (Leichtentritt 1930, 366).