Koizumi Fumio on Nuclear Tones

This article presents an English translation of most of a section from Koizumi Fumio's influential Research on Japanese Traditional Music (Ongaku no Tomo Sha, 1958).The section appearing below is the one in which he introduces the concept of "nuclear tones," which have the gravitational properties of a tonic, but differ importantly in that they come in pairs, not requiring one member of the pair to dominate the other, and in that they neither presume nor encourage an octave-or scale-based way of construing pitch material.Nuclear tones are a necessity for understanding Koizumi's conception of the tetrachord, which remains important in Japanese music analysis to this day.To illustrate his points, Koizumi calls on a diverse range of examples, ranging across many different regions and styles of Japanese music, demonstrating how despite these differences, the nuclear tone remains a vital and useful concept for understanding nearly all of them-and how, in the rare cases when it does not seem relevant, that is a sign about the music's probable origins.Though Koizumi's project in this particular book was Japanese music, he was interested in a wide variety of musics across the world, and theoretical tools of his like the nuclear tone and tetrachord were meant to be similarly widely applicable.I hope that by making this work more visible to the English-speaking world, it may help Koizumi's ideas to reach audiences he had always wanted them to.