Le Marteau sans maître for contralto and six instruments

The Hammer without a Master  is a nine-movement piece composed by Boulez between 1953 and 1955 and first performed in 1955 in Baden-Baden. Boulez was always reluctant to explain his pieces; when he first performed his work his programme notes were quite laconic:

Le Marteau sans Maître, after a text by René Char, written for alto, flute, viola, guitar, vibraphone, and percussion. The text is partially sung, partially interpreted through purely instrumental passages.

The work is considered a master-piece of the post-war avant-garde, and extremely complex serial polyphony is enriched by the use of an original set of instruments.