Dominant 7th Flat 9th guitar chord shapes

Intervals: 1-3-5-b7-b9. A textbook altered dominant, especially in minor keys. The b9 forms a semitone clash with the root but also acts as a leading tone down into the tonic’s 5th or root. In minor iiø–V–i progressions (e.g. Bø7–E7b9–Am), the b9 is almost the default colour, coming naturally from the harmonic or melodic minor scale. In major keys, 7b9 is often used at cadential points or to enrich secondary dominants. You can hear this sound in countless standards and ballads where the melody hits the b9 of V just before resolving. Use it whenever you want a strong, classical-feeling dominant that still sits comfortably in jazz language.