Between 1912 and 1922 Schoenberg came to realize that he was searching for a new method of composition that would provide a new basis for musical structure to replace the old basis of tonality, which he felt was being stretched and distorted too much to remain a unifying structural principle. Instead of using 1 or 2 tones as main points of focus for an entire composition (as key centres in tonal music), Schoenberg suggested using all 12 tones "related only to one another." In such a system, unlike tonality, no notes would predominate as focal points, nor would any hierarchy of importance be assigned to the individual tones.
The new unifying principle in composition would then arise
from the particular order given to a collection of the 12 tones,
an order that would be different for each composition. The basic
order for any one composition came to be known as its
basic set, its 12-tone
row, or its 12-tone series, all of which terms are synonymous.
The basic set for Schoenberg's
Wind Quintet (1924)
is E
-G-A-B-C
-C-B
-D-E-F
-A
-F; for his
String Quartet No.
4 (1936) it is D-C
-A-B
-F-E
-E-C-A
-G-F
-B.
The basic set is not a theme, for it has no specific shape, rhythm, or loudness. It is a backbone, a musical idea that permeates the composition in which it is used. Because of the various principles of composing and manipulating the basic set recognized by Schoenberg and others, it is not often possible nor even desirable to hear the basic set when the composition is performed. This situation has led many people to attack Schoenberg's method as unmusical and as mathematical madness. Such views seem unjustifiable, because, as Schoenberg pointed out, his method specifies only a tiny fraction of the total nature of a composition--certainly no more than composing with tonality specifies.
Schoenberg's best-known pupils were the Austrian composers Anton von Webern and Alban Berg, each of whom wrote 12-tone music. Neither used the idea of the basic set in the same manner as Schoenberg did, and their music differs greatly in many respects from each other's and from Schoenberg's. Other important composers include the Russian-born Igor Stravinsky, the American Roger Sessions, the Austrian-born Ernst Krenek, the Italian Luigi Dallapiccola, and the German Hans Werner Henze. Many, such as Stravinsky (who had earlier criticized the approach severely) and Sessions, began writing 12-tone music after composing much non-12-tone music.
Some composers also have used some of the notions behind the basic set while simultaneously writing tonal music; among them are Schoenberg himself, the Austrian-born Ernst Toch, the American Walter Piston, and the Russian Dmitry Shostakovich. The American composer Benjamin Johnston combined principles of 12-tone music with microtonality (use of intervals smaller than whole tones or semitones). There are no sufficient analytic techniques used by musicians in understanding 12-tone music, which is partly why it remains not very well understood as a total musical phenomenon by composers, performers, and listeners alike. Twelve-tone music is an example of serialism (q.v.) in music.