Pierre Boulez
Perhaps his most famous piece is Le marteau sans maître (The hammer without a master). This piece, finished in 1957, is for a small group of instruments: flute, guitar, vibraphone, xylorimba (a cross between a xylophone and a marimba), percussion and viola and a singer (alto). It has very complicated rhythms and is influenced by jazz, gamelan music, African and Japanese music.