In AP Music Theory, the leading tone is the seventh scale degree sitting a half step below the tonic. It is a tendency tone that resolves up to scale degree 1, which is what gives V and vii° chords their dominant function and makes authentic cadences sound conclusive.
The leading tone is the seventh scale degree when it sits a half step below the tonic. That half step is the whole point. Because it's so close to the tonic, your ear hears it as unfinished and expects it to step up to scale degree 1. In CED terms (PIT-1.E.1), it's one of the named scale degrees you need to identify by name and number, and per PIT-4.A.1 it's a tendency tone, meaning 18th-century voice leading requires it to resolve a specific way.
In major keys, the leading tone is built in. In minor keys, it isn't. The natural minor scale has a subtonic, a whole step below tonic, with no upward pull. That's why the harmonic minor scale raises scale degree 7 by a half step (PIT-1.G.1): composers needed a real leading tone in minor to make dominant chords and authentic cadences work. Any time you see an accidental on scale degree 7 in a minor-key passage, you're almost certainly looking at a leading tone being manufactured on purpose.
The leading tone shows up in more units than almost any other single pitch. In Unit 1 (Topic 1.4, LO 1.4.B) you name it as a scale degree. In Unit 2 (Topic 2.1, LO 2.1.A) it explains why harmonic and melodic minor exist. In Unit 4 it does the heaviest lifting. Tonal music is organized hierarchically around a tonic (PIT-2.H.1), and the leading tone is the pitch that points at that tonic most forcefully. It's why V and vii° both carry dominant function (LO 4.3.A), why a V-I motion creates an authentic cadence (PIT-2.I.1, LO 4.3.B), and why SATB part writing has rules about it. Per PIT-4.A.1, tendency tones must resolve according to stylistic precedent, so when you write or error-check a progression (LOs 4.2.B and 4.1.A), the leading tone needs to resolve up to tonic, especially in outer voices, and it should never be doubled. Doubling it would force parallel octaves or an unresolved tendency tone. Unit 5 cadence identification (LO 5.5.A) leans on it too, since spotting whether scale degree 7 is raised tells you whether you're hearing a true dominant.
Keep studying AP Music Theory Unit 4
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view galleryDominant Function and Cadences (Units 4-5)
The leading tone is the engine inside dominant function. V and vii° both contain it, and its pull toward tonic is what makes V-I sound like an arrival. A perfect authentic cadence is basically the leading tone (plus the bass) doing its job perfectly. Take the leading tone away and the dominant chord loses its punch.
Harmonic and Melodic Minor Scales (Unit 2)
Natural minor has a subtonic, not a leading tone, so composers raise scale degree 7 to create one. That single alteration is the entire reason harmonic minor exists. When you analyze a minor-key piece on the exam, that raised 7th accidental is your signal that a dominant-function chord is in play.
SATB Voice Leading (Unit 4)
Two of the most-tested part-writing rules are about this one note. Never double the leading tone, and resolve it up to tonic when it's in an outer voice. Error-detection questions love planting a doubled leading tone or a leading tone that leaps away instead of resolving.
Chordal Seventh Resolution (Unit 4)
The leading tone and the chordal seventh are the two classic tendency tones, and they're mirror images. The leading tone resolves up by step, the chordal seventh resolves down by step. In a V7 chord you handle both at once, which is exactly the situation part-writing FRQs put you in.
Multiple-choice questions ask you to identify the leading tone by scale degree name, explain why scale degree 7 sounds unstable, recognize how harmonic minor alters natural minor, and explain why the leading tone gives V and vii° their dominant function. It also drives the part-writing FRQs. The 2025 exam's SAQ Q7 asked for a bass line composed under a given melody following 18th-century voice-leading procedures with Roman and Arabic numerals, and that task is graded partly on how you treat tendency tones. In any harmonization or figured-bass realization, resolving the leading tone up to tonic at cadences and avoiding doubling it are points you can win or lose. Error-detection items frequently hide a doubled leading tone or an unresolved one, so scan scale degree 7 first when you're hunting for mistakes. In minor-key dictation and analysis, listen and look for the raised 7th, because it confirms dominant harmony.
Both are names for scale degree 7, but the distance to tonic decides which one you have. A leading tone sits a half step below tonic and pulls upward. A subtonic sits a whole step below tonic (as in natural minor) and has no strong pull. That's why the CED lists both names in PIT-1.E.1, and why minor keys raise the subtonic to a leading tone whenever dominant function is needed.
The leading tone is scale degree 7 located a half step below the tonic, and it resolves upward to scale degree 1.
Natural minor has a subtonic (a whole step below tonic), so the harmonic minor scale raises scale degree 7 to create a true leading tone.
The leading tone is what gives V and vii° chords their dominant function, and it's essential to authentic cadences.
In 18th-century part writing, never double the leading tone, and resolve it up to tonic, especially when it's in the soprano or bass.
The leading tone and the chordal seventh are the two main tendency tones, and they resolve in opposite directions (up and down by step).
In minor-key analysis or dictation, an accidental raising scale degree 7 signals dominant harmony.
The leading tone is the seventh scale degree when it lies a half step below the tonic. It's a tendency tone that resolves upward to scale degree 1, which creates the tension-and-release that defines tonal harmony.
Both label scale degree 7, but the leading tone is a half step below tonic and pulls upward, while the subtonic is a whole step below tonic (as in natural minor) and has no strong pull. Harmonic minor exists precisely to turn the subtonic into a leading tone.
No. Natural minor's seventh degree is a subtonic, a whole step below tonic. Composers raise it a half step (creating harmonic minor) to get a real leading tone for dominant chords and authentic cadences.
No. Since the leading tone must resolve up to tonic, doubling it would create parallel octaves or leave one voice unresolved. AP error-detection and part-writing questions test this rule directly, so check scale degree 7 in every chord you write.
Both chords contain the leading tone, and its half-step pull toward the tonic is what makes a chord sound like it demands resolution to I. That shared tendency tone is why vii° can substitute for V in progressions.
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