AP Music Theory Unit 7 Secondary Function: Applied Chords, Tendency Tones, and Key Change

Secondary dominant

A dominant-function chord (V or V7) that temporarily treats a diatonic chord as a tonic and resolves to that target chord (e.g., V/ii → ii).

Applied dominant

Another name for a secondary dominant; a dominant chord “applied” to a diatonic target chord rather than to the main tonic.

Tonicization

A brief emphasis of a chord through secondary function (like V/x or vii°/x) without establishing a new key as a true modulation.

Modulation

A change of key that is established as a new tonal center, typically confirmed by cadences and sustained harmonic context in the new key.

Leading tone (scale degree 7)

A pitch a half step below the tonic that strongly resolves up to scale degree 1; secondary-function chords introduce a leading tone to the target chord.

Tendency tones

Notes with strong expected resolutions (especially leading tones resolving up and chordal sevenths resolving down) that drive functional harmony.

V/x (secondary dominant notation)

Roman-numeral label meaning “the dominant of x,” where x is the diatonic chord being tonicized (slash is read ‘of’).

V/V

“Dominant of the dominant”: a secondary dominant that resolves to V (e.g., in C major, D or D7 resolves to G).

V/ii

A secondary dominant that resolves to ii (e.g., in G major, V/ii is E major or E7 resolving to A minor).

V/vi

A secondary dominant that resolves to vi (e.g., in C major, V/vi is E major, containing G#, resolving to A minor).

Secondary dominant seventh chord (V7/x)

A secondary dominant with a chordal seventh that tonicizes a target chord; it should resolve with the temporary leading tone up and the chordal seventh down by step.

Chromatic accidental (in secondary function)

An out-of-key alteration that typically appears because the secondary-function chord is built in the temporary key of the target chord (e.g., F# in D7 in C major).

Inversion figures (figured bass)

Numbers added to a Roman numeral to show inversion (e.g., 6, 6/5, 4/3), including when used with secondary-function labels.

V6/5/V

A V7 of V in first inversion (secondary dominant seventh chord targeting V, with 6/5 inversion figure).

V4/3/ii

A V7 of ii in second inversion (secondary dominant seventh chord targeting ii, with 4/3 inversion figure).

Secondary leading-tone chord

A leading-tone-function chord that tonicizes a diatonic chord other than the tonic, labeled vii°/x, viiø7/x, or vii°7/x and resolving to x.

vii°/x

A diminished triad built on the leading tone of the temporary key of x (a half step below the target’s root) that resolves to x.

viiø7/x (half-diminished leading-tone seventh)

A secondary leading-tone seventh chord with a diminished triad plus a minor seventh above the root; commonly occurs when the seventh is a minor seventh above the leading-tone root.

vii°7/x (fully diminished leading-tone seventh)

A secondary leading-tone seventh chord with a diminished triad plus a diminished seventh above the root; often associated with minor-key collections and extra chromatic alteration.

Step vs. fifth root relationship (vii°/x vs. V/x)

V/x has a root a perfect fifth above the target; vii°/x has a root a half step below the target, often producing smoother stepwise bass motion into the target chord.

Cadential confirmation

Evidence for modulation: a cadence (often V–I or V7–I) in the new key that sounds like a true arrival rather than a brief tonicization.

Pivot chord (common-chord modulation)

A chord diatonic in both the old and new keys that is reinterpreted to shift functional meaning and help establish the new key.

Direct modulation (phrase modulation)

A key change without a pivot chord, often at a phrase boundary, where the new key is established immediately (commonly via dominant-to-tonic motion).

Common-tone modulation

A modulation technique that uses a sustained/shared pitch (common tone) while harmonies change around it to bridge into a new key.

Doubling guideline for diminished triads (vii°/x)

In SATB-style writing, typically double the third of the diminished triad rather than the root (the leading tone), to reduce instability and voice-leading problems.