Questions: Voice-Leading Distinctions Between Tonicization and Modulation

Question 1

A passage in C major uses V7/V (a D dominant seventh chord) that resolves to G major, which then moves on to C major functioning as V–I. What is the most accurate harmonic description?

• A. A modulation to G major, confirmed by the authentic cadence on G
• B. A tonicization of G, because the music returns immediately to C major without establishing G as a new tonal center
• C. A pivot chord modulation, with G serving as the common chord between keys
• D. An error, because V7/V cannot resolve directly to V in this context

Answer: (B)

Tonicization is temporary emphasis of a non-tonic chord through an applied chord, with immediate return to the original key. Here V7/V briefly makes G feel like a tonic, but G then functions as V in C major — the original tonal center reasserts itself within the same phrase. A modulation would require G major to be established with its own cadences and sustained harmonic activity, such that C no longer feels like home.

Question 2

After an extended passage in E♭ major, a piece arrives at a B♭ major chord that is then confirmed as the new tonal center by two authentic cadences in B♭. Looking back, an A♭ major chord in E♭ served as ♭VII in B♭. What is this A♭ chord?

• A. A secondary dominant in E♭ that tonicized B♭ temporarily
• B. A pivot chord enabling modulation to B♭ major, functioning simultaneously as IV in E♭ and ♭VII in B♭
• C. A chromatic tonicization that resolved back to E♭
• D. A modal mixture chord borrowed from E♭ minor

Answer: (B)

A pivot chord belongs to both keys simultaneously — it is the hinge on which the modulation turns. A♭ major functions as IV in E♭ major (diatonic) and as ♭VII in B♭ major (also analyzable in that key). When the music then confirms B♭ with cadences, we recognize that the pivot was the moment of transition. This differs from tonicization because the music does not return to E♭ — B♭ becomes the sustained new tonal center.

Question 3

A secondary dominant chord (such as V/V) generally indicates that the music has modulated to the key of its target chord.

• T. True
• F. False

Answer: False

A secondary dominant can either tonicize or initiate a modulation — the chord itself does not determine which. The distinction is what happens afterward: if the music quickly returns to the original key, it was a tonicization; if it settles into the new key with cadences and sustained harmonic activity, it was a modulation. V/V is one of the most common applied chords in tonal music and the vast majority of its appearances are tonicizations, not modulations.

Question 4

In a genuine modulation, Roman numeral analysis in the original key eventually becomes strained — an accumulation of chromatic chords that signals the original key frame no longer applies.

• T. True
• F. False

Answer: True

This is a practical diagnostic tool: if Roman numerals in the original key produce a coherent, mostly diatonic analysis with an occasional chromatic chord, the music has probably only tonicized. But if Roman numerals in the original key generate string after string of chromatically altered chords with no clear function, the original key has been abandoned. At that point, re-analyzing in the new key produces clean, diatonic Roman numerals — confirming modulation.

Question 5

How do you determine through harmonic analysis whether a passage has tonicized a chord or modulated to a new key?

Model answer: Ask whether the original tonic regains its gravitational pull quickly. In tonicization, the applied chord resolves to its target and the progression returns to the original key within a phrase — the chromatic note was a temporary visitor, and Roman numeral analysis in the original key remains coherent. In modulation, the music settles into the new key with authentic cadences, melodic phrases close on the new tonic, and analysis in the original key breaks down (too many chromatic chords with no clear function). The longer and more cadentially complete the passage in the new key, the more clearly it is a modulation.

Duration and cadential confirmation are the key criteria. Tonicization borrows temporarily and returns; modulation relocates and closes in the new key. The Roman numeral test — does analysis in the original key stay clean? — is a reliable practical heuristic for making this distinction in score analysis.