Analysis

Search by function — build a progression. Stack rows in a column to match across keys (each row = one key layer); a 2-row stack is a pivot. Use + row for more layers.

…or search by chord progression — finds the same shape in any key.

T tonic (I, III-, VI-) SD subdominant (II-, IV) D dominant (V, VII°) b borrowed (modal interchange)

Individual Study

Common-chord modulation, C major → G major

The pivot chord (C) is tonic in C and subdominant in G; the D7 then confirms G as the new key.

W. A. Mozart

Symphony No. 40 in G minor, K. 550 — I

Movement 1

A11–9

J1–4 K5–9

B10–17 A218–28

Opening phrase of the main theme (part J).

The opening main theme in the tonic.

Answering phrase that closes A1 (part K).

Bridge that tonicises the relative major (Bb).

Bridge toward the relative major.

Restatement of the main theme.