Does Werther or War and Peace have more acts?
War and Peace (opera) War and Peace (Op. 91) (Russian: Война и мир , "Voyna i mir") is an opera in two parts (an Epigraph and 13 scenes), sometimes arranged as five acts, by Sergei Prokofiev to a Russian libretto by the composer and Mira Mendelson, based on the novel "War and Peace" by Leo Tolstoy. Although Tolstoy's work is classified as a novel, the 1812 invasion of Russia by the French was based on real-life events, and some real-life people appear as characters in both the novel and the opera, e.g. Prince Mikhail Kutuzov and Napoleon Bonaparte.
Die Harmonie der Welt Die Harmonie der Welt ("The Harmony of the World") is an opera in five acts by Paul Hindemith. The German libretto was by the composer.