Karlheinz Stockhausen

Mantra, for two pianos with ring modulation, was a watershed in Stockhausen's development. Composed in 1970, it was the work that not only signalled his return to composing fully notated music after almost a decade in which ''intuitive'' techniques, using graphic and verbal scores, became more and more important, but it also introduced the use of a musical formula, the ''mantra'' of the title, from which every pitch and rhythmic element of the composition is derived by transformation. It was the way that Stockhausen would compose for the rest of his life, and his enormous opera cycle Licht would be based on it.