Benjamin Ives Gilman, The Philosophical Review (1892)
“ For these ancient octave forms themselves another origin must be sought: we may, perhaps, surmise that they are what may be called the natural precipitates of all simpler melody. That these natural interval orders can be formed by a progression of fifths is a wonderful fact: wonderful, too, it must have been to these primitive theorists to see the generative powers of the fifth progression exhaust themselves in the formation of an interval order of twelve equal semitones. In their eyes the fifth progression became the natural foundation of all music. ”
