Shin-Nihon-Ongaku (literally 'new Japanese music') is the 1920s-to-1960s movement that took the vocabulary of Edo-era koto, shakuhachi and shamisen music and grafted onto it Western functional harmony, clearly notated forms, and the modern concert-hall setting. At its centre is Miyagi Michio (1894-1956), who — blind from age four — invented the 17-string bass koto to give the ensemble a low register, standardised tunings closer to Western scales, and wrote compositions with a clear ternary shape. His 1929 Haru no Umi (Sea of Spring), for koto and shakuhachi, became the movement's international signature: an atmospheric water-colour of a coastal spring morning that reads simultaneously as Japanese and as recognisably concert-hall music. The looseness of Edo-period free time is dialled back; the sonata-like dialogue of Western chamber music comes forward.

The movement was named at a single concert: 6 June 1920, at the Aoyama Kaikan in Tokyo, where Miyagi Michio and the modernist songwriter Motoori Nagayo staged a joint programme called Shin-Nihon-Ongaku Ensou-kai — 'the New Japanese Music Concert.' Miyagi had gone blind at four, apprenticed to koto masters at nine, and spent his teenage years in Incheon on the Korean peninsula, where he wrote his first work Water Metamorphoses (Mizu no Hentai) in 1909, aged 15. Meiji-era Japan had institutionally separated Western classical (yōgaku) from traditional music (hōgaku); Tokyo Music School had no traditional department at all. Miyagi's project was the Taishō-democracy answer: create Japanese art music that could stand on the same concert bill as Debussy. The rise of Nipponophone / Columbia Records and the founding of NHK in 1926 gave it the distribution channel.

Listen first for the low bass koto. In Haru no Umi, Miyagi's 17-string bass koto lays down a slow held pattern of waves, above which the 13-string koto plays fast broken chords and the shakuhachi carries the melody. That three-layer texture did not exist in Edo-period sankyoku trio music. Second, notice the metric clarity: 2/4 or 4/4 pulses that a Western-trained listener can count. Third, the ternary form — free-time introduction, main theme, virtuosic finale — is consciously borrowed from classical-era sonata design. Fourth, the shakuhachi's pitch has been tightened so that it can play in tune against Western instruments.

Start with Haru no Umi (Sea of Spring, 1929). The 1954 recording with Miyagi Michio on koto and Yoshida Seifū on shakuhachi is the definitive reading. Then hear Mizu no Hentai (1909) to grasp the raw teenage first work. For a deeper dive: Miyagi's Senoto (1923), Ochiba no Odori (1937), and Nakanoshima Kin'ichi's Three Fragments (1961), which stands at the movement's late-period peak.

Miyagi died in the small hours of 25 June 1956, falling from the overnight express train Ginga between Tokyo and Osaka; he was 62. Whether it was an accident, a stroke, or something else has never been resolved — the writer Uchida Hyakken devoted an essay in his Tokyo Diary to the mystery. Second: because Haru no Umi was written for a New Year radio broadcast under vague pre-war copyright terms, Miyagi never collected most of its royalties; the piece is now the single most-performed Japanese work at New Year, and back-royalties are estimated in the billions of yen.