I started working through the composing exercises in the book “Composing With Constraints, 100 Practical Exercises in Music Composition” by Jorge Variego. I came across Exercise 23 which shows how to use an Axis of Symmetry and I thought the result sounds a little or maybe a lot like some of the musical phrases of Bernard Herrmann (he scored many Alfred Hitchcock films as some of you reading this might well already know). The technique involves three instruments, in this case three violin sections. One instrument serves as the ‘axis’ of notes for a melody (Violins 2 in this example). A certain number of semitones are chosen to then add a note on top of the axis note that many semitones above, and likewise that many semitones below the axis melody note. This is repeated for each note of the axis melody. The number of semitones for each note can be different for each note of the axis melody, or the same, this is the creative part. Thus the melody becomes the harmony.