Tension and resolution: the leading note and its friends

Why does a melody move us? Largely because it plays with our expectations: it creates tension, makes us wait, then resolves it. As in a film, without conflict there is no story. A composer must therefore know which notes "pull" towards others, and how to pace those tensions.

1. Stable and unstable notes

In C major, the notes of the tonic chord (C, E, G) are stable: you can stop on them. The others are unstable and have "tendencies": they want to go somewhere.

Degree	Note (in C)	Tendency
7 (leading note)	B	rises to C (very strong)
4	F	falls to E
6	A	falls to G
2	D	falls to C (or rises to E)

2. The leading note: the most "magnetic" note

B is only a semitone away from C: that closeness creates an irresistible pull. That is why it is called the leading note (leading tone). Listen to it alone, then resolved:

In the G7 chord (G–B–D–F) there are two unstable notes at once: B (rising to C) and F (falling to E). Together they form a tritone, the most tense interval in the scale. When it resolves, the two notes move towards each other and settle on C and E. This is the engine of the perfect cadence.

M:4/4
L:1/4
Q:1/4=72
K:C
%%staves {RH LH}
V:RH clef=treble
V:LH clef=bass
[V:RH] "G7"[FB]4 | "C"[Ec]4 | "G7"[FB]4 | "C"[Ec]4 |]
[V:LH] G,,4 | C,4 | G,,4 | C,4 |]

3. The appoggiatura: tension on the strong beat

An appoggiatura is a note foreign to the chord, placed on a strong beat, that resolves by step onto a chord note. It produces a small expressive "ache", like a sigh. The Romantics adored it. Here every bar begins with an appoggiatura (F over C, B over A minor, A over G, D over C) that resolves downwards.

M:4/4
L:1/4
Q:1/4=66
K:C
%%staves {RH LH}
V:RH clef=treble
V:LH clef=bass
[V:RH] "C"F2 E2 | "Am"B2 A2 | "G"A2 G2 | "C"D2 C2 |]
[V:LH] [C,G,]4 | [A,,E,]4 | [G,,D,]4 | [C,G,]4 |]

Compare it with a version where the melody plays E, A, G, C directly: correct, but far less expressive. Tension gives value to the resolution.

4. The suspension: making the ear wait

A suspension means holding a note while the harmony changes underneath it: it becomes dissonant, then falls by step to resolve. Bach and Handel use it at nearly every cadence.

M:4/4
L:1/4
Q:1/4=66
K:C
%%staves {RH LH}
V:RH clef=treble
V:LH clef=bass
[V:RH] "Am"e4- | "G"e2 d2 | "F"c4- | "G"c2 B2 | "C"c4 |]
[V:LH] A,,4 | G,,4 | F,,4 | G,,4 | C,4 |]

Bar 2: the high E, consonant over A minor, becomes dissonant when the bass moves to G; it resolves to D. Bar 4: same game, the C held over G resolves to B… which finally rises to the closing C.

Pacing tension: think in waves. A phrase starts calm (stable notes), builds tension (unstable notes, dissonances, climax), then relaxes towards the cadence. If everything is tense, nothing is.

Common mistakes:

Abandoning the leading note: a B over the dominant that leaps down instead of rising to C leaves a feeling of incompleteness (unless that is the intended effect).
Resolving by leap: an appoggiatura or a suspension resolves by step; otherwise the dissonance just sounds like a wrong note.
Too many dissonances on strong beats: one appoggiatura per phrase is a jewel; ten is confusion.

Your workshop

Bring your eight-bar melody back into the piano roll.
Look at bar 7: make the melody pass through the leading note (B) over the G chord and rise to the final C.
Add two appoggiaturas: on two strong beats, replace a chord note with the note just above it, then resolve downwards.
Add one suspension before the cadence: hold a note while the bass changes, then let it fall by step.
Listen to the "before" and "after" versions. Write down in your sketchbook what changed in the emotion.

Self-check: does every dissonant note you added resolve by step onto a chord note?