Music Theory for Programmers: Computation and Harmony

Primary Source: https://runjs.app/blog/music-theory-for-programmers
Author: Lukas · Year: 2026 · Publisher: RunJS

Summary

A comprehensive primer on Western tonal and modal music theory explained entirely through mathematical ratios, interval matrices, frequency formulas, and JavaScript algorithms.

Key Points

• Mathematical derivation of 12-TET (twelve-tone equal temperament) from the twelfth root of two ($f=440\times 2^{(n-69)/12}$).
• Algorithmic generation of major, minor, pentatonic, and modal scales using binary step masks.
• Chord construction, inversion arithmetic, and voice-leading heuristics implemented in clean code.

Mentioned Pages

Entities

• Lukas (RunJS)

Concepts

• Algorithmic Harmony
• Equal Temperament Computation
• Frequency Ratios