This package adds tonal / harmonic functions to strudel Patterns.
npm i @strudel.cycles/tonal --save
import { sequence } from '@strudel.cycles/core';
import '@strudel.cycles/tonal';
const pattern = sequence(0, [1, 2]).scale('C major');
const events = pattern.firstCycle().map((e) => e.show());
yields:
(0/1 -> 1/2, 0/1 -> 1/2, C3)
(1/2 -> 3/4, 1/2 -> 3/4, D3)
(3/4 -> 1/1, 3/4 -> 1/1, E3)
play with @strudel.cycles/tonal codesandbox
See "Tonal API" in the Strudel Tutorial