Systematic use of changing meters in consecutive MEASURES of a composition.

This metrical system was introduced by Boris Blacher in his piano work Ornamente, composed in 1950. The device is deceptively simple: the first measure has two eighth notes, the second measure has three eighth notes, etc., following the ascending arithmetical progression, then reversing the process to follow a descending progression. Other German composers adopted Blacher's variable meters, among them Karl Amadeus Hartmann in his concerto for piano, wind instruments, and percussion, and HANS WERNER HENZE in one of his string quartets.