Altered

Dominant seventh, flat nine chords

Dominant 7 with b9: C-E-G-Bb-Db. Formula: 1-3-5-b7-b9. From half-whole diminished or harmonic minor.

In every key

The same shape, moved. The symbols below are spelled the way the app spells them, which is the spelling the chord's own scale asks for rather than whichever accidental is easier to type.

  • C7b9
  • Db7b9
  • D7b9
  • Eb7b9
  • E7b9
  • F7b9
  • F#7b9
  • G7b9
  • Ab7b9
  • A7b9
  • Bb7b9
  • B7b9

Voicings

Written in C, because that is the key the encyclopedia authors them in; every one transposes unchanged.

Rootless Type A (3-b7-b9-5)

E · Bb · Db · G

intermediate

Standard rootless — bass plays C, you play 3-b7-b9-5

Rootless Type B (b7-b9-3-13)

Bb · Db · E · A

advanced

Diminished UST (Edim7 over C7)

E · G · Bb · Db

advanced

C7b9 = Edim7 over C — 4 dominants share each diminished

Cluster b9-3-b7-b9

Db · E · Bb · Db

expert

Where it turns up

Classic V7 of minor. Resolves strongly to im7. Bebop and standard jazz vocabulary.

Commonly swapped with

  • C7
  • C7alt
  • Edim7
  • Gb7