The move to atonality took shape because of many factors: one being that late romantic complex counterpoint gradually had the effect of chorale harmony with some ornamental filigree around it (Wagner’s overture to Lohengrin for example). The overture has the effect of the same melody repeating over and over, the other parts supporting the melody. Contrapuntal parts project a single part with another part as melismatic elaboration.
The gradual move to atonality can be seen in the use of note doublings in Debussy . An octave doubling has generally been seen as ubiquitous (and no cause for alarm), just a reinforcement of a note or an expansion into a different octave. What if you doubled a note (it parallels the primary note and has the same exact same rhythm), not with octaves but with 3rds, 5ths, or both, not as independent voices but as projections of a single note. These doublings would of course exactly follow the principal note — since they are not independent. It is possible that complex and thick textures could be developed from basically two-part counterpoint.
A further elaboration of this idea is the technique called polytonality. Polytonality features parts in different keys at the same time. For example, in a piano work the treble part is in G major with appropriate key signature and the bass part is in a different key, say, A major with an A major key signature. This assures that there will be contrast between the triadic doublings in the composition’s different parts. Polytonality is a misnomer as these resulting chords are not dependent on opposing keys but on contrapuntal voices that are doubled. Further, keys don’t really oppose each other, rather, they blend into distinctive unified harmonic formations that are projections of the lowest note.
Schoenberg’s move to atonality is not much different from Debussy’s except that Schoenberg’s doublings have more chromatic elaborations around the basic doublings, and his elaborations do not move in exact rhythm with the melody or controlling voice. They “hover” around the main notes because they are slightly offset, and there are many more surface parts to double. See Schoenberg’s “Erwartung.”
The two methods mentioned above seem to me to be related. Both break down what we know as common tonality practices. The difference is simply a matter of degree of surface dissonance. (To generalize the French school less, and the German School more.) As this is a practical guide to composition I will leave the question of what is tonality aside, in favor of explaining different recent composers approaches to this problem.
Assignments: Lesson 5
Compose a piano work with an independent slow moving bass and a melody doubled by major triads (major 3rd plus perfect 5th) in root position.
Take the same composition adding chromatic and rhythmic elaborations to the upper triads, to offset them. Also add associated parts to the bass.