In addition to earlier jazz blues workouts : this chorus presents a number of ideas how to combine common voicings with chromatic approach notes to create more complex sounding harmonic and melodic movements.
A good example for this principle is the standard dominant 7 voicing [A7] in bar 2 on beat 4. In conjunction with the underlying harmony which is established by the preceding voicings, it creates an Eb7 b9/#11 sound. At the same time this A7 voicing is also a chromatic approach chord which leads to the following harmony Bb7:
Another example for the use of ‘logical’ chromaticism can be found in bar 4: non-diatonic approach notes are placed on the weak beats and lead to a defining chord tone [b7] of the following harmony [Eb7]:
This structural idea is continued throughout the chorus. See if you recognize approach and target notes in order to come up with your own chromatic moves.
The last three bars show a short and effective idea for a jazz blues ending.