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Sonata in C, K. 545

W. A. Mozart

By Mayank Sanganeria

In C major, this piece is 112 chord changes across 73 bars under the notes on the page — a intermediate-tier piece by our difficulty audit, 81 of 97 in the library, ranked easiest to hardest. Reduced to block chords, that's a progression you can learn in a sitting; the piece you're reading is that progression wearing figuration.

Practice this piece → Practice chords → Learn it section by section → Hear the harmony → Sight-read something new →

What's inside the harmony

Reducing the piece to block chords and labeling every change turns up harmonic phenomena that are easy to miss reading the figuration straight — each one below is also its own corpus-wide census.

• Secondary dominants 17× bar 15: V7/V (A) · bar 17: V7/V (A) · bar 19: viio/V (A)
• Borrowed chords 1× bar 44: bVII (F)
• Chord inversions 40× bar 2: V7 (D) (second inversion, bass D4) · bar 3: IV (C) (second inversion, bass C4) · bar 4: V7 (B) (first inversion, bass B3)
• Seventh chords 40× bar 2: V7 (D) — G-dominant seventh chord · bar 4: V7 (B) — G-dominant seventh chord · bar 5: ii7 (F) — D-minor seventh chord
• Modulation 5× bar 11: bars 11–19: G major (r=0.97) · bar 20: bars 20–24: a minor (r=0.94) · bar 25: bars 25–28: G major (r=0.86)
• Pedal points 4× bar 2: C4 held bars 2–3 under I, IV (C) · bar 11: G2 held bars 11–12 under V, I (G) · bar 43: F4 held bars 43–44 under IV, bVII (F)

Free scores

• Blocked-chord reduction (MusicXML) — the harmony skeleton the player performs
• The piece as written (compressed MusicXML)