@tonaljs/progression !tonal 

> Convert chord list to roman numerals analysis chord and reverse

Usage

ES6:

``js
import { Progression } from "tonal";
`

node:

`js
const { Progression } = require("tonal");
`

API

$3

Given a tonic and a chord progression expressed in roman numeral analysis chords, returns the progression expressed in leadsheet chords.

`js
Progression.fromRomanNumerals("C", ["IMaj7", "IIm7", "V7"]);
// => ["CMaj7", "Dm7", "G7"]
`

$3

The opposite of fromRomanNumerals. Given a tonic and a chord progression expressed in leadsheet chords, returns the progression using roman numeral analysis chords.

`js
Progression.toRomanNumerals("C", ["CMaj7", "Dm7", "G7"]);
// => "IMaj7", "IIm7", "V7"]
``

Resources

- Roman numeral analysis
- Leadsheet chord symbols