OLIVER KNUSSEN/MAURICE SENDAK: "WHERE THE WILD THINGS ARE." Glyndebourne Festival Opera with Mary King, Rosemary Hardy, Hugh Hetherington, Stephen Richardson, Stephen Rhys-Williams, Andrew Gallacher; London Sinfonietta, conducted by Knussen. Arabesque Compact Disc, Z6535-L (with libretto). In his slim picture-book about Max and the bizarre creatures who make him their king before he sails away because he is hungry, Sendak used only 380 words to supplement his magical drawings. Knussen has transformed this classic children's book into an enchanting one-act opera with 26 pieces. The startlingly real CD sound throws the listener right into the middle of Max's dream. Hardy neatly captures Max's little-boy arrogance, and King is the firm Mama (doubling also as Tzippy, the female Wild Thing). The rest of the creatures are appropriately loving and fierce. Knussen uses a wide variety of instruments to emulate Sendak's vision. With Sendak's book in hand, this is a splendid way to introduce your child to the joys of opera.