Definition:
The "twelve-tone system" is a music composition technique developed by the composer Arnold Schoenberg. In this system, composers use a specific order of the twelve notes in the chromatic scale (the scale that includes all the half steps, or semitones, in music). This order is called a "tone row." Composers can use this tone row in different ways: they can play it forward, backward, or upside down (which is called inversion).
The twelve-tone system is a unique way of composing music that involves using all twelve notes of the chromatic scale in a specific order. It was created by Arnold Schoenberg and is used to create complex and innovative musical pieces.