Definition
In classical and Romantic harmony an altered chord is a diatonic chord in which one or more notes are modified chromatically to create a stronger push toward the next chord. The alteration doesn't change the function: it makes it more tense. This entry covers the altered chords of the tonal tradition; for jazz alterations (b9, #9, alt) see the entry on modern altered chords.
The principle
An alteration turns a note into an artificial leading tone: a raised note wants to rise by semitone, a lowered note wants to fall. That is why the notes that already have an expected direction are the ones most often altered.
The main altered chords (in C major)
| Chord | Notes | Origin | Resolution |
|---|---|---|---|
| V+ (augmented dominant) | G–B–D# | raised fifth | D# → E (third of the tonic) |
| V7+ | G–B–D#–F | raised fifth with seventh | D# → E, F → E |
| V7(b5) | G–B–Db–F | lowered fifth | Db → C |
| Altered II (V/V with lowered fifth) | D–F#–Ab–C | fifth of D7 lowered | Ab → G, F# → G |
| I+ (augmented tonic) | C–E–G# | raised fifth | G# → A (toward IV or vi) |
| IV+ | F–A–C# | raised fifth | C# → D (toward ii or V/ii) |
Connections with augmented sixths
Many altered chords are close relatives of the augmented sixth chords:
- the V7(b5) in second inversion (Db–F–G–B) has the same notes as a French sixth on Db;
- the altered II in second inversion (Ab–C–D–F#) is exactly the French sixth that prepares the V in C.
Recognizing this identity helps in analysis: the same chord can be read as an altered dominant or as an augmented sixth chord depending on the bass and the resolution.
Practical rules
- Spell the alteration in the direction of the resolution: D# if it rises to E, Eb if it falls to D.
- The altered note is not doubled.
- The alteration is often introduced by chromatic step in the same voice (G–B–D → G–B–D#): the chromatic motion makes the chord sound natural to the ear.
- Augmented chords (V+, I+) have an internal symmetry: they sound suspended and can resolve in several directions.
Typical mistakes
- Writing Eb instead of D# in the V+: the note seems to want to fall instead of rise.
- Resolving the altered note in the wrong direction (D# → D).
- Using the alteration as pure color without preparation in the classical style: the effect is abrupt.
Examples
- Beatles, “Oh! Darling”: the introduction is an augmented dominant chord that resolves to the tonic.
- Liszt, “Faust” Symphony: the opening theme is built on arpeggiated augmented triads, a symbol of the protagonist's restlessness.
- 19th-century romances and Lieder (Schubert, Schumann): the dominant with raised fifth before the tonic is a frequent expressive gesture.
- Pop and standards: the sequence I – I+ – I6 – I7 (ascending line cliché) uses the augmented tonic as a passing chord.
How to use it in composition
- To give urgency to the final cadence, raise the fifth of the V (V+ → I): the ear hears the push of the D# toward the E.
- The I+ after the tonic prepares the IV with a chromatic movement (G → G# → A): ideal in passages leading to the chorus.
- Use the altered II as a dramatic predominant before the cadential six-four.
Exercise
- Write in four voices in F major: I – IV – V+ – I and I – I+ – IV – V7 – I.
- Write the altered II in G major in second inversion and verify that it is a French sixth.
- At the piano, alternate G7 and G7(b5) before C and describe the difference.
Related topics
Altered chords (b5, #5, b9, #9, alt); Augmented chords and their uses; Augmented sixth chords; Secondary dominants; Line cliché; Chromatic harmony.