Watch the Flat Nine & Bluesy online guitar lesson by Frank Vignola from Essentials: Jazz Standard Soloing
Here we start on a C minor chord and move to an F minor chord. Then, we'll play a 2-5-1 in C minor but using the 2 minor 7 flat 5 or Dm7(b5). This brings on the tonality of the flat nine for the G7 as the Ab (flat nine of G7) is the b5 of Dm7. Using the flat nine over the 5 chord in a minor key is effective. Also, using the pentatonic blues in a minor key works extremely well.
In the 2nd half of the tune, we use a straight 2-5-1 in the key of Db major which is unique. Notice by just moving one note up a half step (Db to D), the chord Db major 7th becomes a Dm7(b5). I start with a bluesy pentatonic lick. The notes of the pentatonic are the notes of the minor chord. We then mix it up with a scalar pattern on the F minor. Then, we dive into the flat 9 sound on the 5 chord going back to the C minor 1 chord and into a classic sounding 2-5-1 riff in Db major using the flat 9 chord tone then back to the 2-5-1 to C minor using the flat nine into a confident concluding blues riff.