Complex sentence: Grisélidis is an opera in three acts and a prologue by Jules Massenet to a French libretto by Armand Sylvestre and Eugène Morand based on the play by the same authors, which itself is based on medieval tales.
Split into simpler sentences: Grisélidis is an opera in three acts and a prologue by Jules Massenet to a French libretto by Armand Sylvestre and Eugène Morand. It is based on the play by the same authors, which itself is drawn from medieval tales.