Secondary dominants, in the wild
That sharped note in bar 12 usually isn't the key changing — it's a secondary dominant: a chord borrowed from another key's V, aimed at a chord that isn't the tonic. Write V7/V, say "five-seven of five", hear "a dominant that pulls somewhere new". Textbooks explain them with four-bar examples; here they are in the music you're actually learning — 750 of them across 72 real pieces, labeled where they happen, playable in context.
Practice with the pieces that use it →
The census
Reducing every piece in our corpus to its harmony and counting the applied chords:
| chord | count | what it pulls toward |
|---|---|---|
| V7/V | 101 | V |
| V7/IV | 89 | IV |
| V7/III | 59 | III |
| V7/vi | 57 | vi |
| V7/iv | 52 | iv |
| V7/ii | 50 | ii |
| V7/v | 46 | v |
| viiø7/V | 45 | V |
V7/V is the workhorse — the most common chromatic move in the corpus by a wide margin. If you learn to spot (and hear) just that one, you've covered a large share of the accidentals you'll meet on a page.
Hear them in real pieces
Each link opens the piece in the harmony player, with every chord labeled — the applied chords read as V7/x above the staff. Bar numbers below point at the first few.
- Arabesque No. 1 C. Debussy 37 applied chords
- Prelude 7 in E-flat major (BWV 852) J. S. Bach 36 applied chords
- Prelude 10 in E minor (BWV 879) J. S. Bach 33 applied chords
- Prelude 21 in B-flat major (BWV 890) J. S. Bach 30 applied chords
- Prelude 13 in F-sharp major (BWV 882) J. S. Bach 25 applied chords
- Prelude 17 in A-flat major (BWV 886) J. S. Bach 23 applied chords
- Arabesque No. 2 C. Debussy 22 applied chords
- Liebestraum No. 3 F. Liszt 22 applied chords
- Prelude 8 in D-sharp minor (BWV 877) J. S. Bach 21 applied chords
- Nocturne in E♭, Op. 9 No. 2 F. Chopin 20 applied chords
- Prelude 7 in E-flat major (BWV 876) J. S. Bach 19 applied chords
- Prelude 12 in F minor (BWV 881) J. S. Bach 19 applied chords
Go deeper
- Train your ear to catch them → Our ear-training site drills the difference between a diatonic V and a V7/V until the chromatic pull is something you hear, not just read.
- The theory: tonicization → Why applied chords work, how to spell them, and how to write your own — the full chapter on our theory site.
- The diminished flavor → Same pull, no root: the applied leading-tone chords (viio7/x) surveyed the same way.
- Learn a piece that uses them → The practice ladder loops eight bars at a time — hear the harmony slowly, read along, then play at tempo.