Which opera has more acts, Einstein on the Beach or Owen Wingrave?
Owen Wingrave Owen Wingrave, Op. 85, is an opera (originally written for a televised performance) in two acts with music by Benjamin Britten. The libretto is by Myfanwy Piper, after a short story by Henry James.
Jone (opera) Jone, ossia L'ultimo giorno di Pompei is an opera in four acts by Errico Petrella. The Italian-language libretto was by Giovanni Peruzzini, after Edward Bulwer-Lytton's famous novel "The Last Days of Pompeii".