24: Octatonic Survival

Earlier I talked a lot about the octatonic scale and how I manufactured new scales and organized them into charts. So what survived after rejecting all that early work? Well, almost all of Lightfall is built on two octatonic scales.

(Gustave Dore)

Part One is the common octatonic scale of alternating tones and semitones: Bb Cb Db D E F G Ab
There are no notes foreign to this scale in the entire movement and it is locked in without modulation or transposition, in the tradition of a number of my earlier works.

Part Two begins with a long horn solo that calmly floats around a close neighbourhood of keys. When the orchestra enters at bar 6 it would seem the movement will be firmly in the key of A major; however, by about bar 35 the music settles into an artificial octatonic scale of A B C C# D E F# G and remains there to the end of the work, again without foreign notes, modulation or transposition. As I composed I thought of this as an A mixolydian tonality with an added C natural, though genuine analysis might find there is something different going on.