Neopolitan What?

I had seen the Neopolitan Sixth (N6) in various music theory books and online posts, but always glossed over it because to me it's name implied some esoteric flavor I'd have little use for (like Neopolitan ice cream, a mash-up of what I experience as three unrelated flavors).

Regardless of it's fancy name (never mind where the 6 in the name comes from), it's nothing more than a bIIMaj7.  As long as the I for the key has been established in the listener's ear, it will resolve back to the I which can be either major or minor.  This is what the GbMaj7 is doing in "The Girl From Ipanema".  It's just a more subtle way of getting back to the home key, F.

To make the N6 (bII7) a little easier to understand, imagine it were a dominant 7 instead of Maj 7.  In other words, imagine that GbMaj7 was written as Gb7.  In the key of F, Gb7 is a tritone sub for C7 (b5). 

When written and played as a major-7 chord, we can note that Dbmaj7 is enharmonic to F- with a b6 in the base. This might be the motivation for the name "Neopolitan 6".  When soloing over it, we might think of it as a variation of a minor-iv chord. That happens often enough that we should already know what to do.

Bridge to Ipanema

This isn't about a bridge you can drive on or walk over.  It's about the "B" section, or "bridge", in Jobim's "Girl from Ipanema". The chords in bridge has confounded me (and lots of other beginners) when considering how to solo over them.  I finally found some helpful links I want to share.

1. Kevin Smith's post
2. M-ster's post
3. M-ster's follow-up post
4. Forum post by Ed Byrne

I found the first three of the above a bit hard to follow, but Kevin Smith has an interesting observation.

To me the point of the bridge is that the first twelve bars "wind up" and the next four "wind down." 

"Girl From Ipanema" is about longing. This "Girl" in the title is a real person.  At the time Jobim encountered her, she was a young teenager.  She would periodically come into a cafe/bistro to buy cigarettes for her mother. It was the same cafe where the young Jobim would sit alone for hours composing songs.  The delicate but perky "A" section evokes the feeling the young, impressionable and lonely songwriter might have gotten while noticing the beautiful, delicate but perky girl in the middle of her errand.

The "B" section evokes the aftermath of that encounter with a four-bar motif repeated three times.  Each four-bar motif is enharmonic to a IV followed by iv in its related key. Together, they evoke a feeling of mounting and unresolvable tension of a man longing to speak to a woman who is unapproachable to him. That is the "wind-up" part.

That tension gets released in the last four bars of the bridge with a stereotypical cycle back to the original key of F major. The first 12 bars evoke a long inward sigh - the "wind up". The last four bars evoke the release of that sigh.

At the end of the B section, the reverie has passed. One more time we hear the A section that evokes the memory of the delicate and perky young woman, carefree and oblivious to the composer's attention and longing.

I tend to favor Ed Byrne's analysis because it's the simplest and therefore easiest for me to understand. It's also perfectly reflects the shifting melody.

Let's rewrite the B section to reflect the key center:

| IV of Db | % | VIIb7 of Db  |  % |

| ii-7 of E  | % | VIIb7 of E     | % |

| ii-7 of F.  | % | VIIb7 of F     | % |

| iii-7 of F   |  VI7b9 of F  |  ii-7 of F  |  V7b9 of F |

The last four bars are a straightforward 3-6-2-5 Tin Pan Alley turnaround in F.

Let's look at the first four bars: 

| Gbmaj7 | % | B7 | % |

If we use the key of the song, Db, as our starting point, we have the IV-chord followed by the VIIb7. A VIIb7 is enharmonic to iv6 in the same key.  So we can think of this as 

| Gbmaj7 | % | Gb-6 | % |

In bars 5-8 we shift everything up a minor third. E becomes our tonic note. F#-7 is the ii-7 in E, and D7 is the VIIb7 in E.  We already established that VIIb7 is enharmonic to iv6.  It so happens that ii-7 is enharmonic to IV6.  So we can rewrite bars 5-8 as:

| IV6 | % | iv6 | % | (in E)

or

| A6 | % | A-6 | % |

Bars 9-12 shift the same cadence up another semitone. So we have the exact same cadence as before, but in F.

I'm not suggesting that anyone pick up a pen and alter the chart for Girl From Ipanema. That would be a crime! I'm only suggesting a different way to think about the bridge when soloing over it, so you can have a coherent mental framework to work with each four bars of the bridge instead of a sequence of seemingly unrelated chords that appear arbitrary even if they sound good. In summary:

1. Bars 1-4: Blow over two bars in Gb major (#4), followed by two bars in Gb melodic ("jazz") minor. 
2. Bars 5-8: Go up a minor third and blow over two bars of A major (#4) followed by two bars of A melodic minor. 
3. Bars 9-12: Do it all over again, but a semitone higher, so Bb major (#4) followed by Bb melodic minor.
4. Bars 13-16: Bring it home to F again with a standard 3-6-2-5 turnaround.

We've heard countless tunes with a major subdominant chord followed by it's parallel minor subdominant. For example F major to F minor followed by C, the I chord. It's a pretty standard but effective device that was used extensively in Tin Pan Alley tunes and probably before. Rhythm Changes section A, bar 6 comes to mind. 

There you have it! Bars 1-12 of the Ipanema bridge are a series of three of these such cadences, but they never resolve. Instead, they climb, first by a minor third, then by a semitone, before the final turnaround in the last four bars bring us back to the final A section.

That was easy! (Not really, but I hope it helps someone else because it sure helped me.)