Tristan und isolde：opera in three acts Die walkure：opera in three acts Ezio HWV 29：Opera in three acts Orpheus：Opera in three acts Tristan und Isolde：A music-drama in 3 acts Lulu：Opera in three acts Moses und aron opera in 3 acts Rigoletto：Opera in three acts Tristan und isolde-prelude to act III Tristan und isolde:Prelude to act III