Plot: Tonight's concert celebrates Glasgow-bom composer Oliver Knussen's 50th birthday with a performance of his two children's operas based on Maurice Sendak 's picture books Higglety, Pigglety, Pop! and Where the Wild Things Are. Knussen himself conducts the London Sinfonietta, of which he is the music director, and a star cast of singers which includes soprano Rosemary Hardy, mezzo-soprano Mary King and bass-baritone David Wilson-Johnson