The flat-V m7b5 thing, a swing tune and a solo.

There’s a common chord substitution that jazz players like to make, especially when the melody sits on the tonic note for a bit (say, a C note in the key of C), over the I-chord. There are a couple of variants, but they all start with a m7b5 chord on the flat-V of the scale, F#m7b5 in the key of C. From there, the chord roots move down chromatically to the tonic.

For example, here are two versions the final four bars of the jazz standard “My Romance,” in C. The first example has the “stock” changes, and the second replaces the final C chord with a chromatic sequence starting on F#m7b5. Notice that every chord has C in the melody.  

Stevie Wonder’s “You Are The Sunshine of My Life” sometimes gets this treatment in the first chord. Compare these two versions of the first phrase in the key of C.

In one band I played with for years, we’d call it “the flat five thing,” which eventually got shortened to “fluhfluh.” You’d be coming to the end of a tune and someone would shout out “Fluhfluh!!” and we’d know what to do, unless one of us vetoed it on grounds of it being “Gratuitous Fluhfluh.” Yes, we were a very silly crew.

This progression sometimes is part of the tune. Here’s one from a series of "counterfeit Gypsy jazz" tunes I wrote once. The recording can be found on my website, www.theotherjocko.com, click on the "Sounds Like..." tab and you'll find it there.  Here's the head.

You could play the chord changes of the "fluhfluhs" in the first part using these voicings.

or:

It's best to break them up though, to add a little textural, rhythmic, and melodic interest:

Here’s a solo I played over it. On the first four chords I never left the tonal center of Ab. Don’t forget, this sequence is a substitution for the tonic chord, so it’s a good idea to think of it aas a thing that happens in the tonic key. That being the case, Dm7b5 in this position is, to me, “Ab-something-with-D-natural-in-it.” I also tend to play the written Dbm7’s as m6 or m(M7), i.e., the I-chord of Db melodic minor, which is also the key of Ab with a b6 and 7 (see "Getting into major scales, pt 3: the Honorary Notes" on this blog, posted 2/16/16).  I guess I should’ve just written the chord as Dbm6, but either one works..

Again, just know the key of Ab well enough that you can alter scale tones at will, and you don’t have to waste a lot of time learning “chord scales,” the “jazz red herring.”