Here is an analysis of the reharmonization from last week, which can be found here.
· The first chord Ab, I replaced with GbMaj7#11 which theoretically is the iv chord in Db major. By doing this I moved the key centre of the song from Ab to Db. I didn’t substitute Ab for another chord with a similar function, instead I chose the same quality but from a different key, based on the colour. And theoretically, this is the explanation for the change. It works because the melody notes relate to the new chord in a beautiful way, in part because Db Major and Ab Major are very similar keys, with only one note difference.
· I replace the next chord (AbMaj7) with a DbMaj7#11, which actually is the iv in the key of Ab, so we come back immediately to the key. Usually, the iv is functionally considered a subdominant chord, but since there is no AbMaj7 in the beginning here, the keys are a bit flowy. A pair of dominant chords follow, so the subdominant function works.
· Aside from all of this thinking, another reason the Gb to Db works is because they are the same quality, and from keys that are very similar, so there is a built-in connection or sense there.
· Chromatic motion is always super smooth, because it creates voice leading. Which means each note in the chord leads smoothly to the next. We have this in the motion of DbMaj7#11 to C7sus
· The next few chords target Bbm as a resolution. Working backwards, B7#11 is a tritone substitute to the original F7, and this B7 is set-up with a another chromatic V7 resolving down to it, you can also think of it as a tritone substitution- But loosely, because tritone substitution involves substituting one V7 chord from melodic minor for another V7 from the same scale, a tritone away.
· Then we switch out Bbm for Gø. This is a diatonic substitution because both chords are from Ab, although viiø chords are in the category of dominant and iim7 are in the category of subdominant. This is ok though because we are switching the purpose of the chord. Instead of leaving that measure at rest, we are putting in a chord that pushes for movement. And naturally we follow the Gø with a V7, which is then completed by the modal interchange FminMaj7, to create a regular minor 2-5-1. Modal interchange because those 4 measures originally had the V-I chord movement in Ab^, which is now replaced by a modal interchange on the relative minor (vi-Fm7). Minor-Major chords have a stronger resolution in a minor 2-5.
· FminMaj7 is a modal interchange chord substituting vi (Fm7) which is a diatonic substitute chord for I (Ab). This is followed by Fm7, and Bb7, a ii-V, acting as a secondary dominant to the imaginary Eb7 that we could place in the measure before Ab7.
· This next section targets Db^7#11, which can be thought of as a diatonic substitute, taking V (the dominant) out and replacing it with IV (a subdominant), which changes the direction of the phrase a bit, giving the Db a resolution feeling, instead of a “moving on to the next section” feeling that a dominant would give. Because Db is from the key though, it still transitions smoothly to Ab.
· The G7 adds a smooth passing from Ab, because notes move chromatically like we talked about before creating voice leading. This is followed by an F#ø which can be thought of as a ii to the tritone substitute (B7) of F7.
· We omit B7 though and instead keep the root and change the chord quality, creating a reference to the beginning of our reharmonization with the Gb and Db chords.
The biggest things you can take away from this article are the concepts of using colour and voice leading. These are probably the most important melodic/harmonic factors in music as a whole. Learning to use these techniques will definitely pay off.
If you have any questions, email me at tetyanahar@gmail.com.
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