Complex sentence: The Sacrifice is an opera in three acts composed by James MacMillan with a libretto by the poet Michael Symmons Roberts based on Branwen story of the Welsh myth collection, the Mabinogion.
Split into simpler sentences: The Sacrifice is an opera composed by James MacMillan with a libretto by the poet Michael Symmons Roberts. The story originates from the Branwen story of the Welsh myth collection, the Mabinogion.