This Micro Lesson runs through a common sounding Jazz Progression in the key of, "Eb Major."
This jazzy progression is quite typical of those found in many of the popular Jazz Standards. It begins from the tonic chord of the key and extends it out to a ninth interval creating the extended "Ebmaj9" from the maj7 chord.
In measure two, the "Bbm7" chord enters and while the root (Bb) is the proper 5th degree of this key center, the chord quality is different. This is explained through a method called "Modal Interchange." This method is an interchange of chord qualities between the major and minor key signatures. So, the "Bbm7" chord is technically being "borrowed" from the parallel key of "Eb Minor."
An extension of an 11th is placed upon this "Minor V-Chord" and it behaves in this harmony to pull-up into an, "Abmaj7," (the proper IV-Chord of the key).
Measure three has a short Pentatonic scale run off of our "Abmaj7" chord and acts to highlight a return into measure four. The "Dominant V" chord of "Bb Dominant" is applied to turn the progression around back to the top. An extension of a 13th is used to strengthen the return to the Tonic chord of "Ebmaj7." Enjoy!
Micro Lesson 220: "Eb Major" Jazz Progression