Harmonic Series Spiral Synth (2021): An in-broswer synthesiser and interactive visualisation of the harmonic series in the form of a logarithmic spiral. This model is based on Erv Wilson’s 1965 publication and Catherine Lamb’s related creative/pedagogical practice. Link (please use on desktop!)

Relations of tone as an analogy for relations of colour (2021): By the late 17th century, Isaac Newton had suggested that the visible spectrum of light seemed to have frequency-like properties when he split white light into its component colours with a prism. This spectrum appeared to occupy a frequency range of approximately one “octave” and, in his Opticks (1704), he proposed musical relationships of tone as an analogy to describe his perceived relationships of colour. In modern terms, this “colour octave” corresponds to wavelengths of light in the range of ca. 380 to 760 nanometres. 380 nm has a frequency of ca. 394,463,760.53 MHz – which would sound roughly 40 octaves above the 11th partial of Pythagorean C1 (32.614 Hz tuned in relation to a Kammerton A4 440.3 Hz). On this page, the colour octave is presented in four musical divisions (rainbows): the equal tempered chromatic scale, the diatonic scale in 5-limit JI, the harmonic series segment 16°–32°, and Partch’s 43-tone scale in 11-limit JI. Various HEJI pitch-classes and their “corresponding” electromagnetic wavelengths in nanometres have been indicated. Link (please view on desktop!)

String instrument physical model (2021): This SuperCollider synth is potentially useful for generating more realistic string timbres, making use of slight inharmonicitiy, synthetic bow attack, bow position, etc.). Included is an example mockup realising James Tenney’s “KOAN” for string quartet. Supercollider file, audio example

The ‘helmholtz-ellis-ji-notation’ package (2020): This package is a simple LaTeX implementation of the Helmholtz-Ellis JI Pitch Notation that allows for in-line typesetting of microtonal accidentals for use within theoretical texts, program notes, symbol legends, etc. Published on CTAN. Link

Plainsound Harmonic Space Calculator (2020): An in-browser JavaScript tool for analysis, composition, and performance preparation of music composed in microtonal just intonation, (version 2.5). Link