How a scale turns into chords - and why some of them pull towards home.
Back to the Music MapT TonicS SubdominantD Dominant
First up
A · Tonic
Home. Everything is at rest – a piece may end on A.
Harmony lens: The notes of the sounding chord light up in the colour of its job, its root is circled. Tap the chord buttons and the accompaniment plays your progression.
A stands on the keynote A itself. Every progression that arrives here sounds finished; every one that starts here tells the ear where home is.
Its notes: A – C# – E
Every chord on this page belongs to this key. Change the root of the key and everything below moves with it - the names change, the relationships do not.
Every chord below is stacked from these seven notes. Tap a key in the circle to select it - its tonic chord plays.
Major · Minor
No accidentals - natural notes only.
Try it
Every degree carries a chord: the degree itself, then every second note above it. Tap one.
The filled dot is each chord's root. Each chord takes a step, skips one, takes the next - and every column starts one step higher than the one before.
What do you notice?
Listen to all seven: which sound bright, which dark – and which one completely different?
What it's called
Diatonic chords – the seven triads of a key – one on every degree, stacked from every other note.
Why
The surprising part: you need nothing new for it. Take the seven notes of a scale, stand on one of them and stack every second note on top - that is a chord. It works on every degree, so every key comes with seven chords.
Watch the labels: capital numerals are major chords, lowercase ones minor, and the small circle means diminished – two minor thirds stacked. Nobody decided that - it falls out of the distances in the scale.
Three major, three minor, one diminished - in every major key, always in this order.
So far this has been about single notes: how they sound, how far apart they are, which ones belong to a key. Harmony starts where several notes sound at the same time.
Everything here is in major, where that pull is clearest. Major and minor themselves are the subject of the key page.
Quick check
Listen to this chord: major, minor or diminished?
Try it
Home. Everything is settled here, and a piece is allowed to end here.
The step away. Something is under way, but without urgency - nothing is decided yet.
The tension. It wants to go back to the tonic, and you can hear it clearly.
What do you notice?
Listen to the three groups: which sounds like rest, which like setting off – and which wants to go back?
What it's called
Function – the job a chord does in its key: tonic (T), subdominant (S) or dominant (D). Tonic is already the name of the key's root itself (Key page) – and of the chord built on it.
Why
And those seven are not equals. Some feel settled, others feel like setting off, and one pulls home so strongly that you hear the ending before it arrives. That is what this page is about.
The colours are the same as in the workshop above: tonic blue, subdominant green, dominant red-brown.
Which degree does which job is an agreement of functional harmony, not a calculation: it can be justified (related chords share two notes, see the next section) but not computed. The letters T, S and D come from Hugo Riemann’s theory of functions.
Quick check
First the tonic, then a second chord – what job does it do?
Try it
2 notes in common with I
2 notes in common with IV
↗ contains the leading tone
2 notes in common with V
↗ contains the leading tone
The third degree resists a clean label: it shares two notes with the tonic and two with the dominant, and it carries the leading tone as well. Depending on what surrounds it, it acts as one or the other. Textbooks disagree here, and both sides have good reasons.
↗ contains the leading tone
What do you notice?
Look at the bands: how many notes does each relative share with the main chord of its group?
What it's called
Related chords – two chords that share two of their three notes – they can stand in for each other.
Why
The same seven chords, now sorted by what they do. Each group has a main chord and a relative that shares two of its three notes with it.
That is why the vi can stand in for the I after the V (the deceptive cadence further down), and the ii works before the V just as well as the IV.
In German functional harmony the relatives are called parallels: vi is the tonic parallel (Tp), ii the subdominant parallel (Sp), iii the dominant parallel (Dp) – even though, as you can see above, it fits the tonic just as well. vii° counts there as a dominant seventh chord without its root.
Quick check
How many notes do I and IV share?
Try it
First the leading tone on its own, then the root of the key above it. That is the entire pull, in two notes.
What do you notice?
Listen to the first note on its own: can it stay like that?
What it's called
Leading tone – the note a semitone below the root of the key – it leads upwards, home.
Why
The dominant contains a note that sits just one semitone below the root of the key: the leading tone. In this key that is B. It does not like staying that close - it pulls up to C, and the whole chord goes with it.
Two chords contain it and therefore do the dominant’s job: V and vii°. The iii contains it too – one of the reasons it sits in between.
The leading tone as a single note: on the key pageIn natural minor the seventh note lies a whole tone below the root of the key, and the pull is weaker. That is why minor likes to borrow the major dominant with its leading tone – which is where harmonic minor comes from.
Quick check
What is the leading tone in G major?
Try it
What do you notice?
Listen to both: which dominant pushes home harder?
What it's called
Dominant seventh chord (V7) – the dominant with a fourth note on top, the seventh.
Why
In G7 a fourth note joins the three notes of the dominant: F, the fourth degree of the key – stacked two degrees above the top note, like every note before it.
B and F are six semitones apart (a tritone) – the most restless interval there is. Both resolve by a semitone, towards each other: B up to C, F down to E. Two notes pull instead of one.
Almost every dominant in pop, blues and jazz is a seventh chord. vii° is related to it too: its three notes are the top three of V7.
All open shapes: the basic chord chartQuick check
Listen closely: is that V or V7?
Try it
Dominant to tonic. The strongest ending there is - the leading tone resolves upwards, and that settles it.
Subdominant to tonic. It arrives as well, but more gently: the subdominant has no leading tone, so the urgency is missing. You know it as the Amen at the end of a hymn.
The progression stops on the dominant. Not an ending but a colon - it sounds as if something else is coming. That is why it sits in the middle of a piece, not at the end.
The dominant promises the tonic - and then the sixth degree arrives instead. It belongs to the same group, but it is minor rather than major. For a moment it sounds like an ending, and then it is not.
What do you notice?
Listen to all four: which arrive, which stay open?
What it's called
Cadence – a closing formula – how a sequence of chords ends.
Why
A closing formula is called a cadence. All four here are the same length and start on the tonic - the only thing that sets them apart is how they end.
The curves are a model, not a measurement: a chord gets one point of tension if it is not the tonic itself, one if it is a subdominant or dominant, and one if it contains the leading tone.
Which cadence is hiding in a progression of your own, the builder further down will tell you.
Quick check
Which of the four cadences was that?
Try it
Goes from home to the dominant, swerves to the vi and comes back via the IV – open enough to repeat forever.
Known from: Let It Be (The Beatles), Don’t Stop Believin’ (Journey), With or Without You (U2), No Woman, No Cry (Bob Marley)
Three chords, three jobs – and then you are home. Jazz standards string them together in ever new keys.
Known from: Autumn Leaves, Fly Me to the Moon, Satin Doll
Only I, IV and V: four bars home, two away, two back, then dominant, subdominant and home again.
Known from: Johnny B. Goode (Chuck Berry), Hound Dog (Elvis Presley), Sweet Home Chicago (Robert Johnson), Pride and Joy (Stevie Ray Vaughan)
What do you notice?
Does one of them sound familiar – and where does the dominant sit in each?
What it's called
Chord progression – a sequence of chords that repeats – the harmonic frame of a song.
Why
The numerals make songs comparable: the songs are in other keys, the degrees are the same. The progressions here sound in the key above.
Each lives from the same play of leaving and coming home – the curve shows where the tension rises.
In the blues each of the three chords carries a minor seventh, even the I and the IV, where it doesn’t belong to the key at all. That very friction is the blues sound.
Quick check
Which jobs follow each other in ii–V–I?
Try it
Four chords, in any order. Tap degrees, listen to the progression - and see whether one of the four cadences comes out of it.
From two chords on, it can tell you whether a cadence is in there.
What do you notice?
Which turn is at the end of your progression?
What it's called
Harmonic analysis – reading a progression for the job each chord does and how it ends.
Why
It is recognised at the end: what makes a turn is its last two chords.
By ear, the same works in the workshop: there your progression runs in a loop, in A major, and three missions ask about endings, pull and open ends.
To the Workshop with the harmony lensTry it
with a barre
diminished – rarely played open
What do you notice?
Which of them can you already play?
What it's called
Open chords – shapes with open strings – comfortable, but only available in some keys.
Why
In the major keys C, G, D most diatonic chords are open – no barre, with open strings. That is why they are the guitar keys par excellence.
What is missing – the diminished chord and everything on sharp and flat notes – is played as a barre; F and B need one already. The CAGED shapes in the chords area move one shape to any spot on the neck.
To the chords: shapes and CAGEDThe chord diagrams come from the basic chord chart – which also has the seventh chords.
All open shapes: the basic chord chartQuick check
In which key can I, IV and V all be played open?