Analysis of “Blue Bossa” - Introduction
Blue Bossa is a tune that, like Autumn Leaves, is comprised mainly of II - V - I progressions in either a minor or a major key. In this case, the two keys are not relative major and minor keys. But the same approach can be employed as is used in Autumn Leaves. Bracket the II - V - I in major with the Major scale of the key and bracket the II - V - I in minor with the Harmonic Minor scale of the key! The form might be described as ABCB since the 2nd four measures and the 4th four measures are the same. The 3rd four measures could be called the bridge since it is in a different key!
Analysis of “Blue Bossa” - The A section
The progression in the 1st four measures is: /Cmi7 / Cmi7 /Fmi7 /Fmi7 /. In the key of C Minor, Cmi7 is the I chord and normally would call for an Aeolian (natural minor) scale which is in the key signature. However, since the chord lasts for two measures, the Dorian scale (BbMajor) is a good choice to get more of a “jazz” minor sound. The Fmi7 should definitely be a Dorian scale (Eb Major) to sound right in the key of C Minor. The Aeolian scale built on F would have a Db in it and would sound strange in the key of C Minor!
Analysis of “Blue Bossa” - The B sections
The 2nd four measures and the 4th four measures are the same so they can be treated the same way. The chord progression is: /DØ /G7b9 /Cmi7 /Cmi7 /. This is a II - V - I progression in C Minor so it can be bracketed with a C Harmonic Minor scale. The B natural in the C Harmonic Minor scale clashes with the Bb in the Cmi7 but may be used as a chromatic approach to C, the root of the Cmi7. Always keep in mind the 3rds and 7ths of the chords and try to emphasize them. Also, it would be good to use some digital II - V - I patterns to develop a strong melodic flow! You can find some ideas about digital patterns in my blog about the II - V - I progression.
Analysis of “Blue Bossa” - The C section
The progression of the C section is: /Ebmi7 /Ab7 /Dbma7 / Dbma7 /. This is a II - V - I progression in Db Major so it can be bracketed with a Db Major scale. Always keep in mind the 3rds and 7ths of the chords and try to emphasize them. Also, it would be good to use some digital II - V - I patterns to develop a strong melodic flow! You can find some ideas about digital patterns in my blog about the II - V - I progression.
Analysis of “Blue Bossa” - A More complex treatment!
Up to this point, I have been recommending “bracketing” chords with a single scale as much as possible to simplify the process because there are less different scale colors to navigate. But, as you become confident improvising on the tune, you will probably want more variety in the sound! So then you may want to change the scale choice with each chord. Many of these choices are already made for you by the function of the chord, the key, and the context (preceding and following chords). Some of these choices are a matter of fact as is indicated below:
Cmi7 - Tonic chord, normally Natural Minor (Aeolian) but could be Dorian (Bb Major)
Fmi7 - IV in minor should be Dorian (Eb Major) to sound normal
DØ - the normal half-diminished scale is Locrian (Eb Major)
G7b9 - Should include alterations which predict the key signature of the Imi7 to follow. The two best choices are the 5th mode of Harmonic Minor (C Harmonic Minor) and G Super Locrian (Ab Melodic Minor)
Ebmi7 - IImi7 should be Dorian to sound like the right key
Ab7 - the largest variety of choices, any dominant 7th scale (except Minor Blues)
Dbma7 - tonic function calls for Db Major scale, Db Lydian (Ab Major) could also be usedWhen embarking on this more complex treatment, be sure to start at a slower tempo and try to emphasize the 3rds and 7ths of chords. These are the most important chord tones in any chord and bring out the quality of the chords (ma7, mi7, dom7,half-diminished, etc.). Listen to recordings by great artists, copy ideas that you like and incorporate them into your solo!