Bb Db F Ab, Eb G Bb Db

Known progressions

• Major ii-V

  ii7 | V7

  In Ab: Bbm7 Eb7

  The building block of jazz harmony: a minor 7th chord on the 2nd degree moving up a fourth to the dominant 7th on the 5th.

• i-IV Vamp

  i7 | IV7

  In Bb: Bbm7 Eb7

  A two-chord vamp of a minor 7th on i and a dominant 7th on IV, both from one Dorian scale.