Benjamin Ives Gilman, The Philosophical Review (1892)
“ It proves that in the series of alternate groups of two and three tones separated by hemitones, which constitutes the diatonic scale, there is a certain note (viz. that below the group of three tones, or F) , and only one, whose hemitone displacement upward will leave the order of the diatonic form; and one, and only one (viz. that above the group of three, or B) , whose displacement downward will have the same result ”
