Music and mathematics, published by one person.
Haidoroya (灰泥屋, haidoroya) is the one-person publishing label of Kengo Ichiki, a physicist who became a programmer, working from Japan. Technical books and essays about music and mathematics, new translations of classics, and an app that turns sound into notes — each one made with the time it deserves. Most of it is in Japanese; this page is about the part that is in English.
Two volumes of a mathematical trilogy, translated from the Japanese originals by the author. Paperback and Kindle, on Amazon worldwide.
From Wave to Note with Mathematics and Code — Kengo Ichiki
How does a wave become a note? Start with sound and pitch, follow the Fourier mathematics, then watch a small program turn audio into MIDI. For curious amateurs, not specialists.
An Exact Calculation in Fluid Mechanics — Kengo Ichiki
Two spheres in a viscous fluid. Their interaction, followed from the Stokes equations to C code and 1,414 exact coefficients — with the human story of research that papers leave out.
Both Kindle editions are in Kindle Unlimited. Read one? Write a review →
One tool, alongside the books. WaoN, a program that turns sound waves into notes, has been in the making since 1996. This is its iPhone, iPad, and Mac version.
Kengo Ichiki
Turn a recording into editable notes. Waveform, spectrogram, and detected notes on one timeline; correct by hand; export MIDI or MusicXML. The first 30 seconds are free, and a one-time purchase unlocks the rest.
Used it? Write a review →
The rest of the catalogue is in Japanese, on Amazon.co.jp. Details on the 日本語のページ.
音楽と数理 — Music and Math
A talking podcast about music, mathematics, and whatever else is on the author's mind, mostly in Japanese, with a run of English episodes on the YouTube channel. The essays above grew out of it.
Kengo Ichiki (市來健吾) was born in Hiroshima in 1968 and holds a doctorate in physics. After research positions in the United States, the Netherlands, and Canada, he returned to Japan in 2009 and became a programmer. He wrote the open-source transcriber WaoN, hosts the podcast Music and Math, and makes Haidoroya's books by himself.
Questions, corrections, and anything else: info@haidoroya.com. In Tokyo, the books are on a shelf at the shared bookshop Honmaru, Jimbocho.