Click any key for its signature, relative minor, diatonic chords, and common progressions. Every chord and scale plays in your browser, and every note is spelled the way the key actually spells it.
Outer ring: major keys. Inner ring: the relative minor that shares its key signature. Every step clockwise adds one sharp, every step anticlockwise adds one flat.
Built by stacking thirds on each degree of the scale, which is where the pattern of three major, three minor, and one diminished chord comes from. Press any card to hear it.
Select a key on the wheel to see its seven diatonic chords, with roman numerals and every note spelled the way that key spells it.
Roman numerals describe a shape rather than a set of chords, which is why the same four numerals work in every key. Play a whole progression, or press a single chord to isolate it.
Select a key and these seven progressions are realised into its actual chords: the four-chord pop loop, the jazz cadence, the twelve-bar blues, and the rest.
Chords and scales are synthesised by a Web Audio oscillator inside this tab, not streamed, and the theory is derived by letter arithmetic rather than looked up in a table. That is why G♭ major arrives with a C♭ in it rather than a mislabelled B.
Hold a single reference tone for as long as you need it, so you can tune to the key you just picked before you play in it.
Put a progression in time. Custom meters, swing, accents, and a trainer that lifts the tempo as you get the changes under your fingers.
Tap along to a song you are learning to find its tempo, then send that BPM straight to the metronome.
Which sharps does this key have, and in what order. What is its relative minor. Which chords belong to it. Where can it modulate without a jolt. All of that is one diagram, because ordering the twelve keys by fifths puts the closely related ones next to each other and the distant ones opposite.
The outer ring holds the twelve major keys, each one a perfect fifth clockwise from the last. The inner ring holds the relative minor that shares its key signature. Click either ring, or tab to a segment and press Enter.
The panel fills with the signature (how many sharps or flats, and which ones in the order they are written) plus the relative and parallel minor, the scale, the seven chords built on its degrees, and the keys sitting one accidental away.
Press the scale to hear it climb and come back down, press any chord to hear it as a held stack of notes, or play a whole progression. What you hear is what is printed: the same notes, in the same spelling.
Every scale takes each letter once and lets the accidental fall where it must, so F♯ major arrives with an E♯ and G♭ major with a C♭. A tool that picks names from a sharp/flat list gets both of those wrong, and a diminished seventh chord loses its double flat.
Majors and relative minors are equally selectable, and the panel switches with them: minor keys get the natural, harmonic, and melodic forms, chords built i ii° III iv v VI VII, and the progressions written for minor.
At the foot of the wheel the sharp side meets the flat side. B and C♭, F♯ and G♭, C♯ and D♭ are each offered as two spellings of one sounding key, with their real signature sizes (five sharps against seven flats) and a note on when each is the one to write.
Chords sound as stacked, sustained oscillator voices and scales run up and back down, generated by Web Audio in this tab. There is a volume control and a stop that actually stops; changing key silences whatever was ringing.
I–V–vi–IV, ii–V–I, the fifties changes, I–IV–V, the twelve-bar blues, vi–IV–I–V, and the Andalusian cadence, each turned into the actual chords of the selected key with the roman numerals kept alongside so the shape stays visible.
Each segment is a real focusable control with an accessible name and a pressed state, the selection carries a border and a bolder label rather than colour alone, and every change is announced through a live region.
Because the fifth is the interval that changes a key by the smallest possible amount. Go up a perfect fifth from C to G and the scale changes by exactly one note: F becomes F♯. Go up another fifth to D and only C becomes C♯. Arrange the keys chromatically instead (C, C♯, D) and neighbours would differ by five or seven accidentals, which tells you nothing useful. The circle sorts keys by how much they share, so distance on the wheel is a direct measure of harmonic distance.
A major scale is two identical four-note halves (whole, whole, half) joined by a whole step. The upper half of C major, G A B C, is the lower half of G major. Building the rest of G major reuses D and E unchanged and needs only its own leading note, F♯, to finish the pattern. Every clockwise step repeats that trick, adding exactly one sharp; every anticlockwise step does the mirror image, adding one flat.
F♯ C♯ G♯ D♯ A♯ E♯ B♯ is itself a circle of fifths: each name is a fifth above the last. That is not decoration, it is a consequence: since each new sharp key adds one sharp and the new sharp is always the leading note of the new key, the sharps accumulate a fifth apart. The flat order, B♭ E♭ A♭ D♭ G♭ C♭ F♭, is the same sequence read backwards, a circle of fourths. It also means you can name a key from its signature: the last sharp is the leading note, so one step up gives the tonic, and the second-to-last flat is the tonic itself.
The relative minor of C major is A minor: the same seven notes and the same empty key signature, but with A treated as home instead of C. It sits on the inner ring directly inside its major, and moving between the two changes the centre of gravity without changing a single note. The parallel minor of C major is C minor: the same tonic, but with three flats. It is three steps around the wheel, not one, which is why borrowing a chord from it (a minor iv, a ♭VI, a ♭VII) registers as a real change of colour rather than a passing detail.
On a piano they are the same twelve pitches; on paper they are not the same key. C♯ major needs seven sharps, including B♯; D♭ major needs five flats. A performer reading D♭ has two fewer accidentals to track and no note that looks like it should be a different letter, so D♭ is the usual choice. The same reasoning makes B major (five sharps) far more common than C♭ major (seven flats). Context wins when it disagrees: if a piece is already in C♯ minor, its parallel major is written C♯ major rather than dropped into D♭, and a passage modulating sharpwards stays on the sharp side rather than switching sides mid-phrase. F♯ and G♭ are the genuine coin toss, at six accidentals each.
A place to modulate that costs nothing to set up. The five keys within one accidental of your own share six of their seven notes with it, so you can pivot on a chord that belongs to both and arrive somewhere new before the listener registers a change. For a songwriter that is the bridge that lifts, the last-chorus key change that does not sound like a gimmick, and the reason a chorus in the relative minor still sounds like the same song. The tool marks them on the wheel and lists why each one qualifies.
It is not true acoustically. A pure fifth is a 3:2 frequency ratio, and stacking twelve of them multiplies the pitch by (3/2)^12, which is about 129.7, while seven octaves is 2^7, exactly 128. The two miss each other by roughly 23.5 cents, a quarter of a semitone known as the Pythagorean comma. Equal temperament closes the gap by shaving every fifth to 700 cents instead of 701.955, so the error is spread evenly and invisibly across all twelve. The wheel is a picture of that compromise: it only closes because we agreed to detune every fifth by two cents in exchange for being able to play in all twelve keys.
Count the steps. To play a song in E♭ using open shapes, walk from E♭ round to a friendly key: D is one step anticlockwise, which is a semitone down, so a capo on the first fret restores concert pitch while you play everything in D. Going the other way, a B♭ trumpet sounds a whole step below what it reads, so a part in concert B♭ must be written in C: two steps clockwise on the wheel. An E♭ alto sax reads a major sixth above concert pitch, three steps clockwise. Because the wheel is ordered by fifths, every one of those moves is a count of segments rather than a semitone calculation, and the chord panel shows you what the new key's chords are once you land.
Because that is what the key signature says. The signature of A minor is the signature of C major, and the chords that follow from those seven notes are i ii° III iv v VI VII. Real music then raises the seventh degree constantly, which turns the minor v into a major V and is exactly the alteration harmonic minor exists to describe. The Andalusian cadence in the progression list ends on that borrowed major V. The scale switch in the panel lets you see natural, harmonic, and melodic side by side, so the raised notes are visible rather than silently baked into the chord list.
Nothing is uploaded, no account is needed, and no audio file is fetched. The theory is derived in your browser and the sound is synthesised by a Web Audio oscillator in this tab. You do not need to read notation: the wheel names the keys, the panel names the notes and the chords, and the play buttons let you check by ear that what you are reading is what you are hearing.
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