Random Chord Generator

What this generator does

Builds a chord from a random root and quality, and shows the notes it is made of. Chords are stacked in thirds from the root by letter name — C, then the third letter up, then the third above that — and the accidentals are then chosen to produce the interval each quality requires. Spelling a chord this way is what makes C-E♭-G a C minor triad rather than a 'C-D♯-G' that no notation program will accept.

How to use this tool

1. Choose which chord qualities are in the draw — major and minor triads, sevenths, diminished, augmented, suspended.
2. Choose whether to draw from practical roots or all twelve.
3. Press Draw chord.
4. Name the notes before you look, then play it.

Understanding the controls

Chord qualities

Which types are in the draw. Triads are three notes; sevenths add a fourth and are the backbone of jazz and blues; diminished and augmented are symmetrical and unstable; suspended chords replace the third rather than alter it, which is why they sound neither major nor minor.

Root range

Practical roots are the twelve chromatic notes in their common spellings. Extending to all spellings includes roots like B♯ and F♭, which exist in real music but are rare enough to be a theory exercise rather than a practice one.

Show intervals

Adds the interval of each note above the root — major third, perfect fifth, minor seventh. That is what actually defines the quality, and reading it alongside the notes is how the spelling stops being arbitrary.

Worked examples

C minor

C E♭ G — root, minor third, perfect fifth.

F♯7

F♯ A♯ C♯ E — a dominant seventh: major third, perfect fifth, minor seventh.

B♭dim7

B♭ D♭ F♭ A𝄫 — every interval a minor third, which is why it is symmetrical and can resolve four ways.

Dsus4

D G A — the third is replaced by a fourth, so the chord is neither major nor minor.

Common use cases

• Practising chord shapes without always reaching for the same four
• Drilling chord spelling for a theory exam
• A guitarist working through voicings up the neck
• Ear training — play the chord, then identify what makes it that quality
• Finding an unfamiliar starting point when writing

How this generator works

A chord is stacked in thirds: from the root's letter, the engine steps two letter names for each chord tone, so a C chord uses C, E, G, B regardless of quality. It then assigns each note the accidental that produces the required interval above the root — a major third is four semitones, a minor third three, a diminished fifth six. Deciding the letter first and the accidental second is what keeps the spelling legal, and it is why a diminished seventh chord contains a double-flatted seventh rather than a note that merely sounds like a sixth.

Randomness and fairness

The root and the quality are drawn independently using the browser's cryptographic random number generator, so any allowed combination is equally likely and repeats are possible. The notes are then calculated, not drawn — the spelling is a consequence of the root and quality and involves no randomness. A seed makes the sequence reproducible.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

• It gives notes rather than voicings, so it will not tell you where to put your fingers or which inversion to use.
• There is no audio and no chord diagram — the output is names and intervals.
• Extended chords beyond the seventh are not included; the useful ninths and thirteenths depend heavily on context and voicing rather than on a spelling rule.
• Chord symbol conventions vary between jazz, classical and pop notation. The tool uses one consistent set and names it.
• A random chord has no key context, so some draws will be theoretically valid and musically odd. That is the nature of drawing at random rather than a fault.

Common mistakes

Spelling a minor third as an augmented second

C to D♯ and C to E♭ sound the same and are different intervals. In a minor triad the third must be a kind of E, so it is E♭.

Treating a suspended chord as major or minor

It is neither — the third has been replaced, so the thing that decides major or minor is not there. That is why it wants to resolve.

Assuming any seventh chord is a dominant seventh

Cmaj7 has a major seventh, C7 has a minor seventh, and they do completely different jobs. The symbol matters.

Practical tips

• Say the notes before you play the chord; if you can only find it by shape, you do not yet know it.
• Draw ten chords and play them all in one position before moving on, so you are practising the voicing as well as the chord.
• Pair this with the scale generator: play a scale, then draw chords and work out which ones belong to that key.

Privacy and your data

Nothing is entered and nothing is stored. Chords are calculated in your browser; none of them is uploaded or written into the page address, and analytics records only which qualities were enabled.

Frequently asked questions

Why does a diminished seventh chord have a double flat?

Because every interval in it is a minor third, and the seventh has to be a kind of seventh above the root. Stacking three minor thirds from B♭ gives D♭, F♭ and then A double flat — which sounds like G, but calling it G would use the wrong letter and break the chord's spelling.

What is the difference between Cmaj7 and C7?

The seventh. Cmaj7 has B, a major seventh above C, and sounds settled. C7 has B♭, a minor seventh, and pulls strongly towards F. They are not interchangeable.

Can I use this for guitar?

Yes, but it gives you the notes rather than a shape. That is arguably more useful once you are past the first few chords — knowing that F♯7 is F♯ A♯ C♯ E lets you find it anywhere on the neck rather than in one memorised position.

Why do some chords look strange?

Because the draw has no key context. B♭dim7 spelled correctly contains a double flat and looks alarming; in the key it belongs to it is completely ordinary.