Questions: Chromatic Alterations and Mixture Harmony

Question 1

In a piece in C major, a composer uses the chord F–Ab–C (F minor, iv). A student says, 'The piece has temporarily modulated to C minor.' What is wrong with this analysis?

• A. The chord F–Ab–C does not exist in C minor
• B. A single borrowed chord creates a momentary color change without establishing a new tonal center — this is mixture, not modulation
• C. Modulation requires the borrowed chord to be tonicized with its own dominant
• D. The student is correct; using any chord from the parallel minor counts as modulating to that key

Answer: (B)

Mixture (modal borrowing) and modulation are fundamentally different: mixture brings a chord from the parallel key for coloristic effect while the tonal center remains in the original key; modulation actually shifts the tonal center to a new key. A single borrowed iv chord in C major creates a darkening effect without leaving C as the home key — we're still hearing C major with a borrowed color, not C minor as a new tonal center. Modulation typically requires establishing the new key with a cadence or prolonged presence.

Question 2

In C major, a voice has the note Ab drawn from a borrowed iv chord. According to mixture voice-leading principles, where should this Ab resolve?

• A. Up to A-natural, restoring the diatonic scale degree
• B. Down to G, resolving stepwise in the direction of the lowering
• C. It can move freely in any direction since it is a borrowed tone
• D. Down to F, because Ab is the third of the iv chord and thirds typically fall

Answer: (B)

The voice-leading rule for chromatic mixture is that altered tones resolve in the direction of their alteration: lowered tones resolve downward, raised tones resolve upward. Ab is a half-step lowering of A-natural, so it resolves down to G — its nearest diatonic neighbor in the downward direction, typically as part of a V or I chord. Resolving Ab upward to A-natural creates a cross-relation (Ab and A-natural in close proximity across voices), which clashes with the intended darkening effect.

Question 3

The iv chord in a C major passage is a borrowed chord because it contains Ab, the lowered sixth scale degree drawn from the C natural minor scale.

• T. True
• F. False

Answer: True

In C major, the diatonic sixth scale degree is A-natural, producing a IV chord of F–A–C (F major). C natural minor has Ab as its sixth scale degree. Borrowing iv from C minor introduces Ab into the C major context. This single chromatic alteration — one half step — produces the characteristic darkening effect of mixture. The chord is 'borrowed' because it belongs natively to the parallel minor key, not to the major key where it appears.

Question 4

Chromatic mixture and modulation are essentially the same technique — both involve using pitches from outside the home key to create variety.

• T. True
• F. False

Answer: False

Mixture and modulation differ fundamentally in their effect on tonal center. Mixture temporarily borrows chords from the parallel key for coloristic effect while remaining anchored in the original key — the tonic does not change. Modulation actually shifts the tonal center: the music establishes a new key, often confirmed by a cadence. Mixture is a momentary visit; modulation is a move. A borrowed iv chord in C major is mixture; establishing F minor as a new home key with its own authentic cadence would be modulation.

Question 5

A composer borrows the bVI chord (Ab major) into a passage in C major. What chromatic pitches does this introduce, where do they come from, and how should they resolve?

Model answer: In C major, bVI is Ab–C–Eb. The chromatic pitches are Ab (lowered 6th) and Eb (lowered 3rd); C is already diatonic. Both Ab and Eb come from the C natural minor (Aeolian) scale. According to mixture voice-leading principles, lowered tones resolve downward: Ab resolves down to G (the 5th scale degree), and Eb resolves down to D (the 2nd) or to C. This typically means bVI moves to a V chord (where G is present) or to I. The result is a smooth, darkening harmonic color followed by a return to diatonic territory.

Understanding where the altered tones go is the practical skill of mixture harmony. Without careful resolution, borrowed pitches create cross-relations and awkward leaps. The rule 'lowered tones resolve down, raised tones resolve up' keeps the borrowed harmony expressive and the voice leading smooth.