serial music, or the theory or practice of composing music based on a series of notes in an arbitrary but fixed order without regard for traditional tonality it
Serialism is a compositional method in which one or more musical parameters – pitch, duration, dynamic level – is ordered in a fixed series and repeated (at different pitch levels, or in inversion or retrograde) throughout the course of a work. For composers writing atonal music in the first decades of the 20th cent., total freedom proved hard to sustain, and Arnold Schoenberg in particular looked for a way of systematizing this language. His system, using ‘twelve notes only related to each other’, first introduced in 1923, was to prove hugely influential (and increasingly dogmatically prescriptive) in Western music for more than 50 years — Andrew Clements