The Modulation That Isn't Heard
A Year 12 student is analysing their own composition for the Musicology component. The work is in D major. The student's analysis claims a 'modulation to B minor in the bridge (bars 25–32), prepared by the F# minor chord in bar 24'. Looking at the score, bar 24 contains an F# minor triad, bars 25–28 alternate B minor and G major chords, and bars 29–32 return to D major via an A7 chord. The melody in bars 25–32 uses only notes of the D major scale, and the bass moves B–G–B–G–A. The student's aural recollection is that the bridge 'feels like a new key'. The teacher must decide how to guide the analysis.
1. Assess the student's modulation claim against the harmonic and melodic evidence.
Read the worked answer
The claim is weak on the evidence given. A modulation to B minor would normally be confirmed by a cadence in B minor, a sustained B minor tonal centre, and melodic material using B minor's characteristic notes (including the raised leading tone, A#, in cadential contexts). Here:
- Bars 25–28 alternate B minor and G major - a i–VI oscillation in B minor, but equally a vi–IV oscillation in D major. Neither reading is confirmed by a cadence.
- Bars 29–32 return to D major via A7, which is V7 of D. That is a return, not a continuation, which suggests the bridge never left D.
- The melody uses only D major scale notes, so there is no melodic signal of B minor.
- The bass B–G–B–G–A outlines a stepwise approach to A, consistent with a prolonged predominant in D.
The most defensible analysis is a tonicisation or modal colouring - the bridge emphasises vi (B minor) and IV (G) without establishing B minor as a key. Calling it a modulation overstates the evidence.
2. Explain why the student's aural impression and the score evidence diverge, and how the analysis should be written to accommodate both.
Read the worked answer
The divergence is common and instructive. A listener hears the bridge as 'new' because the harmony moves away from the tonic and the vi–IV oscillation has a different colour from the verse. That perceptual shift is real, but 'sounds different' is not the same as 'modulates'. The student has translated an aural impression into a technical term without checking whether the term's conditions are met.
The analysis should be rewritten to distinguish the two levels:
- Harmonic fact: bars 25–32 prolong vi and IV within D major, returning via V7. No cadence in B minor occurs.
- Perceptual effect: the move to vi creates a temporary darkening and a sense of departure, which the student can describe as a tonicisation of vi or a modal shift in colour.
A sentence such as 'The bridge tonicises B minor through a vi–IV oscillation without cadential confirmation, producing a sense of departure while the tonic remains D' is accurate, uses the right terminology, and preserves the student's musical observation. The lesson is to test an aural claim against the score before naming it.