Commentators on the music of Louis Andriessen have not been slow to point to the perceptible influence of a number of other composers and musical styles. Conspicuously absent from recent discussions of Andriessen's music is the name of Hanns Eisler. Eisler's example, as defined both by his ideas about music and politics, and by the music itself, loomed larger than any other at precisely the time-the early 1970s -when Andriessen was formulating his mature style. More particularly, the model established by Eisler and Brecht in their Lehrstücke (learning plays) provided a framework for Andriessen's own attempts to reconcile popular and progressive elements within a politically committed context. In 1972 Andriessen was invited by the theatre director Paul Binnerts to work on Brecht and Eisler's best known Lehrstück, Die Massnahme. Andriessen wrote new music for the piece which sought to remain faithful to the spirit of Eisler's original settings but which also departed from them in significant ways, partly because of the influence of Reiner Steinweg's interpretation (published in 1971) of the Lehrstück as a fundamentally dialectical exercise. Eisler's attitudes toward musical material and performance, and the basic principles of the Lehrstück, both continue to resonate in Andriessen's later music, even after overtly political concerns have receded from the foreground.