Webern - Symphony, Op. 21

Webern's Symphony, Op. 21 is extremely concise, lasting roughly 10 minutes in performance despite containing two movements. This brevity is characteristic of Webern's mature twelve-tone compositions.

The symphony has two movements: a first movement with sonata-like proportions and a second movement comprising a theme and six variations. Both movements use strict twelve-tone serialism.

The symphony is scored for a small chamber orchestra including clarinet, bass clarinet, two horns, harp, and strings with single players per part. This sparse instrumentation contributes to the work's signature pointillist texture.

Despite its title, it is a compact chamber work rather than a large-scale symphony in the tradition of Beethoven or Mahler. Webern calls it a 'symphony' in reference to its formal structure and the interplay of its two movements, not its duration or forces.