Which opera has more parts including acts and tableaux, Le roi d'Ys or Stiffelio?
Stiffelio Stiffelio is an opera in three acts by Giuseppe Verdi, from an Italian libretto by Francesco Maria Piave. The origin of this was the novel “Le pasteur d’hommes”, by Émile Souvestre, which was published in 1838. This was adapted into the French play "Le pasteur, ou L'évangile et le foyer" by Émile Souvestre and Eugène Bourgeois. That was in turn translated into Italian by Gaetano Vestri as "Stifellius"; this formed the basis of Piave's libretto.
Les fêtes d'Hébé Les fêtes d'Hébé, ou Les talens lyriques ("The Festivities of Hebe, or The Lyric Talents") is an "opéra-ballet" in a prologue and three "entrées" (acts) by the French composer Jean-Philippe Rameau. The libretto was written by Antoine Gautier de Montdorge (1707–1768). The work was first performed on 21 May 1739 by the Académie royale de musique at its theatre in the Palais-Royal in Paris..