Leading-tone exchange chord
The leading-tone exchange chord is the chord that arises from a triad when one note is swapped for its leading tone. C major becomes E minor (C becomes B), A minor becomes F major (E becomes F). Both chords share two notes and are third-related.
- Formation in major
- root falls a semitone (C → B)
- Formation in minor
- fifth rises a semitone (E → F)
- From C major
- E minor (E–G–B)
- From A minor
- F major (F–A–C)
- German functional theory
- Gegenklang (Tg)
A note moves by a semitone
The idea is simple: you take a triad, leave two notes in place and move the third by a semitone. With a major triad the root sinks to the leading tone. C–E–G becomes B–E–G, so E minor. With a minor triad the fifth rises to the note above: A–C–E becomes A–C–F, so F major. The change between the two chords is a very small step, because the chords share two notes and the third voice moves only a semitone.
C major and its leading-tone exchange chord E minor
The C in the C major chord sinks a semitone to B, E and G stay in place. That makes E minor. The note B is known as the leading tone of C major.
A minor and its leading-tone exchange chord F major
In minor the exchange goes in the other direction: the E of the fifth rises a semitone to F. A and C stay in place, and A minor becomes F major.
In the glossary: Substitute chord · Triad
| Starting chord | Exchange | Leading-tone exchange chord |
|---|---|---|
| C major | C → B | E minor |
| G major | G → F♯ | B minor |
| F major | F → E | A minor |
| A minor | E → F | F major |
| E minor | B → C | C major |
| D minor | A → B♭ | B♭ major |
Third relation
Two triads that lie a third apart and share two notes are called third-related. Besides the relative, the leading-tone exchange chord is one of the two closest relationships of this kind. German functional theory calls the leading-tone exchange chord the Gegenklang (counter-chord): in C major E minor is the tonic counter-chord (Tg).
Effect
Because only one voice moves by a semitone, the change sounds soft and yet transforming: major becomes minor without the harmony moving far. It suits gentle transitions without leaving the key. In 19th-century harmonic sequences the leading-tone exchange occurs frequently, for example in mediant relations; in the context of neo-Riemannian theory it is called the operation “L”.
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Related terms
Substitute chordTriadFunctional theoryRelative keyDiatonic chordMediant
Editor: Maik Krohm · reviewed on 3 October 2026
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