Brian Ferneyhough wrote Cassandra's Dream Song in 1970/71. The piece is played from two opposing stands, each sheet of music containing very different material. The piece draws its name from Greek mythology and portrays the conflict between Apollo and Cassandra.
Cassandra: the most unfortunate of the daughters of Priam and Hecuba. Apollo loved her and promised that if she would give him her love in return, he would teach her to see the future. Cassandra consented but did not keep her word once the god had granted her the gift. In return, he took away people's belief in her utterance.
The battle between the oppressed Cassandra (represented by the powerful linear drone of page one) can be violent and aggressive but this tension is at the root of Ferneyhough's composing technique. One pole sets up the system for the generation of structure. The other pole "cheats", disobeys the system.
The piece uses many "extended techniques" and the work's percussive opening is a nice counterpoint to a section of a scene in Christa Wolf's book Cassandra, a Novel and Four Essays in which Cassandra dreams that she has obtained the power of sight.
I saw Apollo bathed in radiant light... The sun god with his lyre, his blue although cruel eyes, his bronzed skin, Apollo, the god of the seers, who knew what I ardently desired: the gift of prophecy, and conferred it on me with a casual gesture which I did not dare to feel was disappointing; whereupon he approached me as a man. I believed it was only due to my awful terror that he transformed himself into a wolf surrounded by mice and spat furiously into my mouth when he was unable to overpower me.
Cassandra later learns the meaning of the dream: "if Apollo spits into your mouth... that means that you have the gift to predict the future. But no one will believe you."
The struggle both technically and emotionally is intense throughout the piece. This represents Cassandra's attempts to speak once again with her own voice. The piece draws energy from the struggle of the performer to come to terms with the technical demands of the piece. It contains sections which the composer himself admits are "not literally realisable". It is a work that moves away from perceived notions of speech resemblance in music and threatens even to replace the gesture as the critical structural element, the gestural object itself threatens to break up, being replaced with a shimmering web of energy exchange.