Chord Generator

Chord Generator is an application that allows you to look up the chords on your favorite musical scale. Not only can you read what the chords are, you can hear them - just by clicking on their cells. For more information about how it works, see the documentation below.

Choose a scale to find the chords it contains.

Key C♭ C C♯ D♭ D E♭ E F F♯ G♭ G A♭ A B♭ B Scale Aeolian Discordant Minor Dorian Dorian ♭6 Dorian ♭9 Dorian ♭9 ♭4 Dorian ♭9 ♯11 Harmonic Major Harmonic Minor Harmonic Minor ♭5 Hungarian Ionian Ionian Augmented Jazz Minor Locrian Locrian ♭♭7 Locrian ♯6 Lydian Lydian Augmented Lydian Augmented ♯2 ♯3 Lydian Augmented ♯3 Lydian Dominant Lydian Dominant ♭9 Lydian ♭3 Lydian ♯2 Lydian ♯2 ♯5 Major Melodic Minor Melodic Minor ♭5 Melodic Minor ♯5 Minor Lydian Augmented Mixolydian Mixolydian ♭13 Mixolydian ♭9 Phrygian Phrygian Dominant Phrygian ♭4 Romanian Semilocrian Semilocrian ♭♭7 Superlocrian Superlocrian ♭♭6 Superlocrian ♭♭6 ♭♭7 Superlocrian ♯6 Ultralocrian ASCII friendly

Results

Here are the chords derived from the scale. Click on any cell to hear it played.

Audio Controls

Volume (%): 0 100

Duration (ms):

Waveform: Sine Square Sawtooth Triangle

Octave: C-1 (8.176 Hz) - B-1 (15.434 Hz) C0 (16.352 Hz) - B0 (30.868 Hz) C1 (32.703 Hz) - B1 (61.735 Hz) C2 (65.406 Hz) - B2 (123.47 Hz) C3 (130.81 Hz) - B3 (246.94 Hz) C4 (261.63 Hz) - B4 (493.88 Hz) C5 (523.25 Hz) - B5 (987.77 Hz) C6 (1046.5 Hz) - B6 (1975.5 Hz) C7 (2093.0 Hz) - B7 (3951.1 Hz) C8 (4186.0 Hz) - B8 (7902.1 Hz) C9 (8372.0 Hz) - B9 (15804.3 Hz) C10 (16744.0 Hz) - B10 (31608.5 Hz)

C Major

C Major: C, D, E, F, G, A, B

Chord Types	C	D	E	F	G	A	B
Fifth	C Power Fifth C5 C, G	D Power Fifth D5 D, A	E Power Fifth E5 E, B	F Power Fifth F5 F, C	G Power Fifth G5 G, D	A Power Fifth A5 A, E	B Tritone BT B, F
Triad	C Major Cmaj C, E, G	D Minor Dmin D, F, A	E Minor Emin E, G, B	F Major Fmaj F, A, C	G Major Gmaj G, B, D	A Minor Amin A, C, E	B Diminish 5th Bdim5 B, D, F
Seventh	C Major 7th Cmaj7 C, E, G, B	D Minor 7th Dmin7 D, F, A, C	E Minor 7th Emin7 E, G, B, D	F Major 7th Fmaj7 F, A, C, E	G 7th G7 G, B, D, F	A Minor 7th Amin7 A, C, E, G	B Minor 7th Flat 5th Bmin7-5 B, D, F, A
Ninth	C Major 9th Cmaj9 C, E, G, B, D	D Minor 9th Dmin9 D, F, A, C, E	E Minor 7th Flat 9th Emin7-9 E, G, B, D, F	F Major 9th Fmaj9 F, A, C, E, G	G 9th G9 G, B, D, F, A	A Minor 9th Amin9 A, C, E, G, B	B Minor 7th Flat 9th Flat 5th Bmin7-9-5 B, D, F, A, C
Eleventh	C Major 11th Cmaj11 C, E, G, B, D, F	D Minor 11th Dmin11 D, F, A, C, E, G	E Minor 11th Flat 9th Emin11-9 E, G, B, D, F, A	F Major 9th Sharp 11th Fmaj9+11 F, A, C, E, G, B	G 11th G11 G, B, D, F, A, C	A Minor 11th Amin11 A, C, E, G, B, D	B Minor 11th Flat 9th Flat 5th Bmin11-9-5 B, D, F, A, C, E
Thirteenth	C Major 13th Cmaj13 C, E, G, B, D, F, A	D Minor 13th Dmin13 D, F, A, C, E, G, B	E Minor 11th Flat 13th Flat 9th Emin11-13-9 E, G, B, D, F, A, C	F Major 13th Sharp 11th Fmaj13+11 F, A, C, E, G, B, D	G 13th G13 G, B, D, F, A, C, E	A Minor 11th Flat 13th Amin11-13 A, C, E, G, B, D, F	B Minor 11th Flat 13th Flat 9th Flat 5th Bmin11-13-9-5 B, D, F, A, C, E, G
Added Ninth	C Major Add 9th Cmaj add9 C, E, G, D	D Minor Add 9th Dmin add9 D, F, A, E	E Minor Add Flat 9th Emin add-9 E, G, B, F	F Major Add 9th Fmaj add9 F, A, C, G	G Major Add 9th Gmaj add9 G, B, D, A	A Minor Add 9th Amin add9 A, C, E, B	B Diminish 5th Add Flat 9th Bdim5 add-9 B, D, F, C
Suspended	C Suspend Csus C, F, G	D Suspend Dsus D, G, A	E Suspend Esus E, A, B	F Suspend Sharp 4th Fsus+4 F, B, C	G Suspend Gsus G, C, D	A Suspend Asus A, D, E	B Suspend Flat 5th Bsus-5 B, E, F
Suspended Seventh	C Suspend Major 7th Csus / maj7 C, F, G, B	D Suspend 7th Dsus / 7 D, G, A, C	E Suspend 7th Esus / 7 E, A, B, D	F Suspend Sharp 4th Major 7th Fsus+4 / maj7 F, B, C, E	G Suspend 7th Gsus / 7 G, C, D, F	A Suspend 7th Asus / 7 A, D, E, G	B Suspend 7th Flat 5th Bsus / 7-5 B, E, F, A
Sixth	C Major Add 6th Cmaj add6 C, E, G, A	D Minor Add 6th Dmin add6 D, F, A, B	E Minor Add Flat 6th Emin add-6 E, G, B, C	F Major Add 6th Fmaj add6 F, A, C, D	G Major Add 6th Gmaj add6 G, B, D, E	A Minor Add Flat 6th Amin add-6 A, C, E, F	B Minor Sharp 5th Add Sharp 11th Bmin+5 add+11 B, D, F, G
Sixth/Ninth	C Major Add 6th Add 9th Cmaj add6 add9 C, E, G, A, D	D Minor Add 6th Add 9th Dmin add6 add9 D, F, A, B, E	E Minor Add Flat 6th Add Flat 9th Emin add-6 add-9 E, G, B, C, F	F Major Add 6th Add 9th Fmaj add6 add9 F, A, C, D, G	G Major Add 6th Add 9th Gmaj add6 add9 G, B, D, E, A	A Minor Add Flat 6th Add 9th Amin add-6 add9 A, C, E, F, B	B Diminish 5th Add Flat 6th Add Flat 9th Bdim5 add-6 add-9 B, D, F, G, C
Added Eleventh	C Major Add 11th Cmaj add11 C, E, G, F	D Minor Add 11th Dmin add11 D, F, A, G	E Minor Add 11th Emin add11 E, G, B, A	F Major Add Sharp 11th Fmaj add+11 F, A, C, B	G Major Add 11th Gmaj add11 G, B, D, C	A Minor Add 11th Amin add11 A, C, E, D	B Diminish 5th Add 11th Bdim5 add11 B, D, F, E

Documentation

What is Chord Generator?

Chord Generator is a application for enumerating all possible chords in a selected scale. In particular, Chord Generator will show what the chord is for a given chord type and position, if such a chord exists. This app even allows you to hear the chord by clicking on the cell.

Usage

There are two set of controls for Chord Generator. The main set, "Choose a scale to find the chords it contains", allows you to select a scale for analysis:

• Key: This sets the root note for the scale. Select from C, C♯, D♭ and all up to B.
• Scale: This sets the scale under study. There are plenty to choose from, such as Major, Dorian (a mode of the Major), and Harmonic Minor. For a listing of all the scales used in the app, see the appendix
• ASCII friendly: By default, the app prints out the Unicode character "♭" for the flat symbol and "♯" for the sharp symbol. If these are displayed as blocks, it probably it means you are using an browser like IE6. Click "ASCII friendly" to see ASCII equivalents like "b" and "#".

Results

Chord Generator generates a table organised as follows:

• The left hand column shows different chord types. Triads are three note chords, where the 1st, 3rd and 5th notes are chosen from a scale starting from a position in that scale. Sevenths are when the 1st, 3rd, 5th and 7th notes are chosen from a scale starting from a position in that scale. For more explanation about how the term chord types are used, see the explanation in the appendix.
• The top row indicates the starting position of the chord in the scale. The first position in a C major scale is "C", the second position is a "D", and so on. Roman numerals are used to indicate position.
• The intersection of a column and a row show the name of chord for that position and that chord type. It also shows the abbreviation and the notes that make it up.

Let's take the C major scale as an example.

1. The first triad is C, E, G – a major chord, or "maj" for short.
2. The second and third chords are D, F, A and E, G, B – D minor and E minor chords.
3. The fourth and fifth triads are F, A, C and G, B, D – F major and G major chords.
4. The sixth is A, C, E – A minor. The seventh – B, D, F is what I call "Diminished Fifth". This should not be confused with "Diminished Seventh", which is a different chord.

The default shows the chords for the C major scale, with "ASCII Friendly" mode turned off.

Audio

Chord Generator (as of version 0.7) not only allows you to read the chords in a given scale, it allows you to hear them as well. Simply click on a cell, and the browser – assuming you are using the right browser – will play the chord contained herein. The parameters for the sound are set in "Audio Controls", the supplementary control set for this app:

• Volume: From 0% (silence) to 100% (full gain).
• Duration: Specifies the length of time (in milliseconds) to play the chord.
• Waveform: The shape of the tones used for the chords. The default is "Sine" (extremely mellow, with no supplementary harmonics), but other choice are "Triangle", "Sawtooth", and "Square".
• Octave: Specifies the frequency range for playing the base note of a chord. Choose lower values for bass tones, and higher values for treble frequencies.

Questions

You may have none, some or many. Some of those questions may be of the form "What the hell is a "Minor Added 6th Added 9th?" For this particular chord, the answer is "It's the chord with the 1st, 2nd, 3rd, 5th and 6th notes of a major scale." For other chords, I'd advise using a search engine. I made this application because I wanted to; any educational usage is just a bonus.

I'd like to extend this app to show what notes are in an chord - such as "Minor", without the need to provide a key. It would be nice to add functionality that shows how the chord may appear on a fretboard, whether it be a guitar, a violin, or a 4/5/6 string bass. But perhaps I will never have time to do anything about it.

Installation and Dependencies

You can get Chord Generator from PyPI through the command:

pip install chordgenerator

Once installed, just add "chordgenerator" to your INSTALLED_APPS list in settings.py, and add the desired URL in one of the urls.py files.

There are two Python dependencies. Apart from Django, the app depends on musictheory. This package – also made by myself – is the guts of the application, and can be used outside of Django. It contains classes for musical temperaments, scales and chords.

The audio component of Chord Generator depends on the JavaScript library jQuery. It also requires the browser to support the experimentatal, HTML5ish Web Audio API, "a high-level JavaScript API for processing and synthesizing audio in web applications". Fortunately, most desktop browsers as of 2014 support Web Audio API, with Internet Explorer being the usual exception. There are no other JavaScript dependencies (thank god) for Chord Generator – no mucking around with dodgy third-party libraries!

The HTML template file used to generate HTML has been redesigned to work with the Mezzanine CMS, which comes with jQuery built in. The redesign removed any explicit references to particular stylesheets found with earlier versions. Feel free to customise: the app is released under a 3 clause BSD license. If you wish to do any changes to the app, pop over to the GitHub repository. (There is also a Github repository for musictheory.)

For more information about the amazing Web Audio API, see Creating Sound with the Web Audio API and Oscillators and HTML5 Web Audio API Tutorial: Building a Virtual Synth Pad.

History

• 0.1 (May 1st 2011) - Initial release. Took code and made setup script.
• 0.2 (May 11th 2011) - Remove bugs.
• 0.3 (June 6th 2011) - Add license information. Add more scales.
• 0.4 (June 2nd 2013) - Try to make a half-decent PyPI package.
• 0.5 (January 30th 2014) - Updated to be compatible with Django 1.6 and Mezzanine 3.0.
• 0.6 (February 15th 2014) - Added more styling to be compatible with Bootstrap. More history described.
• 0.7 (August 27th 2014) - Added the ability for users to hear the chords.
• 0.8 (March 1st 2017) - Updated to be compatible with Django 1.10.
• 0.9 (December 5th 2020) - Updated for Python 3 compatibility.

Copyright © Peter Murphy 2011–2024.

Appendix

This is a little preliminary explanation about the concepts and "theory" behind the application.

Chord Types

These are the chord types used for selecting notes from a scale for playing and displaying.

• Base note: the starting position or first note of each scale. Useful for hearing single tones in isolation and comparing their sound to their chords.
• Fifth: the first note and fifth note of a scale. Useful for power chords.
• Triad: the first, third and fifth notes of a scale. Basically, enough for interesting music.
• Seventh: the first, third, fifth and seventh notes of a scale. When harmonics get interesting.
• Ninth: the first, third, fifth, seventh and ninth notes of a scale. When chords get jazzy.
• Eleventh: the first, third, fifth, seventh, ninth and eleventh notes of a scale. When chords get too jazzy for their own good.
• Thirteenth: the first, third, fifth, seventh, ninth, eleventh and thirteenth notes of a scale. The aeons are closing in.
• Added Ninth: the first, third, fifth, and ninth notes of a scale. Makes me think of the Foo Fighters for soem reason.
• Suspended: the first, fourth and fifth notes of a scale. Pinball Wizard territory.
• Suspended Seventh: the first, fourth, fifth and seventh notes of a scale. Built on suspended chords.
• Sixth: the first, third, fifth, and sixth of a scale. These are often inversions of seventh chords.
• Sixth/Ninth: the first, third, fifth, sixth and ninth notes of a scale.
• Added Eleventh: the first, third, fifth, and eleventh notes of a scale. Added for completeness.

That's probably enough flexibility to select every possible interesting chord. Note that the more 'complicated' chord one is, the more melancholy and or discordant the result generally is.

Scales

There are a whole load of "scales" used in this app, most of which most people would not have heard of. Fortunately, most of the scales are modes and transpositions of other scales. Most of the terminology is grabbed from such places as Solfege and Dolmetsch. One of the few exceptions is the "Discordant Minor", which I invented for shit and giggles.

For reasons of space, alternative names for scales are shown in brackets underneath. I've also introduced gratuituous hyphens to make everything fit.

Scales of interest

Scales	Pattern	2nd Mode	3rd Mode	4th Mode	5th Mode	6th Mode	7th Mode
Major (Ionian)	1-2-3-4-5-6-7	Dorian	Phrygian	Lydian	Mixo-lydian	Aeolian	Locrian
Melodic Minor (Jazz Minor)	1-2-♭3-4-5-6-7	Dorian ♭9	Lydian Augmented	Lydian Dominant	Mixo-lydian ♭13	Semi-locrian	Super-locrian
Harmonic Minor	1-2-♭3-4-5-♭6-7	Locrian ♯6	Ionian Augmented	Romanian	Phrygian Dominant	Lydian ♯2	Ultra-locrian
Harmonic Major	1-2-3-4-5-♭6-7	Dorian ♭6	Phrygian ♭4	Lydian ♭3	Mixo-lydian ♭9	Lydian ♯2 ♯5	Locrian ♭♭7
Discordant Minor (Melodic Minor ♭5)	1-2-♭3-4-♭5-6-7	Dorian ♭9 ♭4	Minor Lydian Augmented	Lydian Dominant ♭9	Lydian Augmented ♯2 ♯3	Semi-locrian ♭♭7	Super-locrian ♭♭6
Harmonic Minor ♭5	1-2-♭3-4-♭5-♭6-7	Super-locrian ♯6	Melodic Minor ♯5	Dorian ♭9 ♯11	Lydian Augmented ♯3	Hungarian	Super-locrian ♭♭6 ♭♭7