#cli #music #theory #chords #jazz

nightly bin+lib kord

A tool to easily explore music theory principles

13 unstable releases (3 breaking)

0.4.2 Jan 16, 2023
0.4.1 Jan 12, 2023
0.3.1 Dec 29, 2022
0.2.2 Dec 26, 2022
0.1.4 Dec 22, 2022

#689 in Command line utilities

Download history 106/week @ 2022-12-17 119/week @ 2022-12-24 52/week @ 2022-12-31 61/week @ 2023-01-07 52/week @ 2023-01-14 11/week @ 2023-01-21

184 downloads per month

MIT license


Build and Test codecov Version Downloads GitHub all releases Documentation Rust License:MIT


A music theory binary and library for Rust (capability playground).

Binary Usage



iwr https://github.com/twitchax/kord/releases/latest/download/kord_x86_64-pc-windows-gnu.zip
Expand-Archive kord_x86_64-pc-windows-gnu.zip -DestinationPath C:\Users\%USERNAME%\AppData\Local\Programs\kord

Mac OS (Apple Silicon):

curl -LO https://github.com/twitchax/kord/releases/latest/download/kord_aarch64-apple-darwin.zip
unzip kord_aarch64-apple-darwin.zip -d /usr/local/bin
chmod a+x /usr/local/bin/kord


curl -LO https://github.com/twitchax/kord/releases/latest/download/kord_x86_64-unknown-linux-gnu.zip
unzip kord_x86_64-unknown-linux-gnu.zip -d /usr/local/bin
chmod a+x /usr/local/bin/kord


$ cargo install kord

Help Docs

$ kord -h

A tool to easily explore music theory principles.

Usage: kord.exe [COMMAND]

  describe  Describes a chord
  play      Describes and plays a chord
  loop      Loops on a set of chord changes, while simultaneously outputting the descriptions
  guess     Attempt to guess the chord from a set of notes (ordered by simplicity)
  listen    Records audio from the microphone, and guesses pitches / chords
  help      Print this message or the help of the given subcommand(s)

  -h, --help     Print help information
  -V, --version  Print version information

Describe A Chord

$ kord describe Cmaj7

   major 7, ionian, first mode of major scale
   C, D, E, F, G, A, B
   C, E, G, B

Play A Chord

$ kord play Bb7#9#11

   dominant sharp 9, altered, altered dominant, super locrian, diminished whole tone, seventh mode of a melodic minor scale, melodic minor up a half step
   B♭, C♭, D♭, E𝄫, F♭, G♭, A♭
   B♭, D, F, A♭, C♯, E

Loop Through Chord Changes

$ kord loop -b 120 "Em7b5@3^2" "A7b13@3!" "D-maj7@3^2" "G7@3" "Cmaj7@3^2"

Guess A Chord

$ kord guess C F# D# A
   fully diminished (whole first), diminished seventh, whole/half/whole diminished
   C, D, E♭, F, G♭, A♭, B𝄫, B
   C, E♭, G♭, B𝄫
   C, D, E♭, F, G, A♭, B♭
   C, E♭, G♭, A
$ kord guess C G Bb F#5 F
   dominant sharp 11, lydian dominant, lyxian, major with sharp four and flat seven
   C, D, E, F♯, G, A, B♭
   C, F, G, B♭, F♯
   minor 7, dorian, second mode of major scale, major with flat third and flat seven
   C, D, E♭, F, G, A, B♭
   C, F, G, B♭, F♯
$ kord guess E3 C4 Eb4 F#4 A#4 D5 D4
   half diminished, locrian, minor seven flat five, seventh mode of major scale, major scale starting one half step up
   C, D, E♭, F, G♭, A♭, B♭
   E, C, D, E♭, G♭, B♭, D

Guess Notes / Chord From Audio

$ kord listen

Notes: C3 E3 G3
   C, D, E, F, G, A, B
   C, E, G

Library Usage

Add this to your Cargo.toml:

kord = "*" #choose a version


use klib::known_chord::KnownChord;
use klib::modifier::Degree;
use klib::note::*;
use klib::chord::*;

// Check to see what _kind_ of chord this is.
assert_eq!(Chord::new(C).augmented().seven().known_chord(), KnownChord::AugmentedDominant(Degree::Seven));
use crate::klib::base::Parsable;
use klib::note::*;
use klib::chord::*;

// Parse a chord from a string, and inspect the scale.
assert_eq!(Chord::parse("Cm7b5").unwrap().scale(), vec![C, D, EFlat, F, GFlat, AFlat, BFlat]);
use klib::note::*;
use klib::chord::*;

// From a note, create a chord, and look at the chord tones.
assert_eq!(C.into_chord().augmented().major7().chord(), vec![C, E, GSharp, B]);


cargo test




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