Atonal Composition

How to write a composition Atonally really.

Berg and Strauss pushed tonality to its limits. They took inspiration from the jazz by adding 7ths and 9ths. They took the basic triad and kept on adding thirds. A good way is to slightly alter a chord, giving it more lead and pull towards where it is going. Notes can be added to the triads as well. This pushes the notes towards their resolution. Voice leading must be considered when doing this.

the Twentieth Century was split into different ways of looking at harmony. One attitude is to let harmony just happen whilst focusing entirely on voice leading. Dissonant intervals just occur. Debussy is completely different as he just focuses on how the colours sound. Sometimes, he would have 10 different semitones in one chord and just three in the next. Messian is amazing for that kind of thing. Skryabin made the mystic chord; it goes C Fsharp Bflat E A D. this has no intension of moving as there are no leading notes present. Messian made chords from 3rds and semitones giving it icy qualities. He then wrote a chord based on 4ths afterwards.

First we have the Quasifunctional style of writing atonally. This means that every chord has a function whether it be the dominant of the next chord or the subdominant etc. It doesn't have to relate to the tonic though.

Second is the Colouristic approach. Here it's all about the colours that are produced from extreme harmonies. It is the quality of the chord that matters and not the progression. 

Finally there is the static evolving harmony. Here the tonal centre weakens. You can replace notes with different intervals. An octave becomes a 7th say. You can alter notes such as sharpen a note in the minor key. Look at the lines, do they have direction? If so, why don't you spice the flavour a bit by adding a flat, sharp or natural. If two notes are going to say C and E at the same time, why not sharpen or flatten them in the direction they are going. This creates leading notes. There is more direction now and more anticipation. It is acceptable to do this for the tonal exercise. In the late romantic period they would sharpen the fifth to push it a bit more. The sense of tonality breaks down.

All this can lead to interrupted cadences. Wagner's prelude to Tristan and Isold avoids the resolution completely by leading up to a cadence and then bottling out. Arnold Schoenberg's Op. 11 No. 1 is great for note leading. He anticipates but does not deliver. It is so good. in one bar, he uses 11 out of the 12 pitches. 12 note aggregate, it fills in the space. After this piece was written, Schoenberg decided to make the 12 note row. The piece is based on cells that have undeveloped character. It is a combination of thirds and semitones. It goes 3, 1, 3, 1, etc. He does this vertically as well as horizontally.