As far a studying key centers, there is no such key as "A melodic minor."
A melodic minor is a scale. A major and A minor are key centers.
The melody contains a significant G natural throughout this section, not
available with a A melodic minor scale.
>
>[G major]
>G6 | % | Cmaj7 | % | C#m7b5 | F#7b13 | Bm(maj7) | Bm7 |
>I | | IV | | #ivm7b5| V7/iii | iii(maj7)| iii |
There is no #iv chord in G major. The IV of G major is C, as you have
shown. C# is from another key: Bm. C#m7b5 - F#7b13 is iim7b5 - V7 of Bm.
>
>D7/A | % | Abo | % | Gmaj7 | Em7(9) | Bm7 | % |
>V7 | | bIIo | | I | vi | iii | |
In G, there is no bii chord. Am is the only ii chord in G. If you have
accidentals beyond the one sharp (F#), then you are no longer in the key of
G.
>
>D7/A | % | C#7/G# | % | Em6/G | F#7b13 | Bm7 | % |
>V7 | | V7/V/iii| | V7sus/iii| V7/iii | iii | |
Em6/G is a C#m7b5 chord in second inversion so it's just a ii chord in Bm.
Considering that this tune begins and ends with Bm, it might be better to
analyze the tune in that key. Anthing else is a stretch.
Bm is in 2#s. Typical modulations move to keys one accidental away, so for
Bm that would be 1# or #3s. 2#s is also the key of D. 1# is G or Em, 3#s is
A major or F# minor. So in B minor, typical modulations would be to its
relative major (D) the iv chord (Em) and its relative major (G), and to the
key of A and its relative minor (F#m), the dominant key.
Try analyzing the tune with those keys centers in mind.
_______________________________________
Bert Ligon
Director of Jazz Studies
_______________________________________
School of Music
University of South Carolina
Columbia, SC 29208
Voice: (803) 777-6565
Fax: (803) 777-2151
http://www.music.sc.edu/Departments/Jazz/
bligon@mozart.sc.edu
_______________________________________