The Pull of the Dominant: The Leading Tone and the Tritone
The last lesson said the dominant is the chord that wants to resolve. That is a claim about a feeling, and feelings are a bad place to stop. The pull is a note, and once you can point at it you can hear it deliberately instead of vaguely.
One semitone from home
In C major, the V chord is G–B–D.
Look at the B. It is the seventh degree of the scale, and it sits one semitone below C — the closest any note gets to the tonic without being it. The ear treats that distance as unfinished business: a step this small reads as almost there, and almost-there wants to arrive.
That note has a name that says exactly this. It is the leading tone, because it leads, and it leads to one place.
Play G–B–D and then C–E–G, and listen only to the B. It moves up by a semitone into the C, and that single move is most of what you hear when a piece of music ends.
Everything else about the dominant follows from this. It is not a restless chord that happens to contain a leading tone; it is the chord built ON the leading tone’s neighbours, and its restlessness is that note’s restlessness.
Why the subdominant feels different
Compare IV — F–A–C in C major. Every note in it is comfortable. There is no semitone reaching for anything, so the chord moves without pulling: it says we have gone somewhere and not we must go back.
That is the whole difference between departure and tension, and it is audible in one listen if you know what to listen for.
Add the seventh and the pull doubles
Take the V chord and stack one more third on top. In C major that gives G–B–D–F, the dominant seventh, written V7.
The new note is F, and it is not decoration. It creates a second semitone that wants to move — F leans down to E — and it puts an interval inside the chord that you have already met.
Count from B up to F: six semitones. That is the tritone, the interval the lesson on interval quality called the one with no plain name and the most distinctive sound in the twelve.
So a dominant seventh contains the most unstable interval in the system, and the two notes making it are each a semitone from where they are going:
B rises to C. F falls to E. The tritone opens outward into a third, and the chord resolves.
Two voices moving by semitone in opposite directions, at the same time, and both arriving. Nothing else in tonal harmony resolves that hard, which is why V7 is the most common chord in Western music after the tonic itself.
The pull is why progressions have a direction
This is the reason the lesson before could talk about home, away, tension, home as a sentence rather than a list. The tension has an address: it does not merely want to move, it wants to move to I specifically, and the leading tone is what makes that address specific.
It is also why V–IV sounds like retreating and IV–V sounds like building. The dominant is the far point of the journey. Everything before it is approach; everything after it is arrival.
Common mistakes to avoid
- Thinking V7 is “V but jazzier”. The seventh makes the resolution stronger, not fancier. It is the plainest chord in a blues for exactly that reason.
- Hearing the tritone as a wrong note. It is unstable on purpose. The instability is the mechanism.
- Expecting the leading tone to be the highest note. It is the third of the V chord and can sit anywhere in the voicing. Its pull comes from its distance to the tonic, not its position.
Now play
The drill below plays a progression with the last chord missing and asks what completes it. Every one of them has been set up so that the answer is the one the pull points at.
Do not work it out from the numerals. Play the progression, and let the unfinished chord tell you where it was going — the whole point of this lesson is that the answer is audible before it is calculable.