What is this change??

[Reg]

Yea... I tend to see and hear at typical approach for playing. The tritone theory aspect is just old school expansion of traditional Tritone sub approach, (inverting actual tritone to create new Dom. chord)... but expanding to become tritone Root approach subs. And then also using Related Chords from Common Chord Patterns, in the example... II V's.

And when actually playing many players... also expand the choice of Scales to create extensions with those subs from Chord Patterns... in the example, sounds like use of MM with use of II's and their related V's.

Back in the 70's I would have just labeled as Contiguous II V's. Almost becomes constant structure application.

When your performing, it's loose because goes by so fast the strong weak aspect almost takes control. But when arranging or composing... slows down enough to where you actually can apply detailed organization, the theory thing.

[rpjazzguitar]

It’s a reharmonization move sometimes known as "side slippin' ". There is a tune by Duke Pearson called "Disapproachment" which is another funny term for these chromatic borrowed ii V's

These moves are usually done by pianists in the moment. They also will do a ii V move simply up a half step.
For example
4 bars of The "Work Song" like |G-7 | C7 | G-7 |C7|
becomes:
G-7 C7| Ab-7 Db7 | G-7 C7 | G-7 C7| In the moment...

Bass player does not know when a pianist will do this, but can hear it happen and attempt to join in. If bass can't catch it then it still works. per Monty Alexander

The ii V "up a half step" is commonly used in situations where the underlying ii V just continues for too long. The half step up feels like a kind of suspension and, to my ear, clearly wants to resolve back to the original ii V.

In contrast, the ii V followed by the "tritone-ii-V", doesn't resolve coherently, to my ear. Which is why, I suspect, that I can't think of a song that does it. After the first ii V, say Gm7-C7, that C7 begs for resolution, most commonly to Fmajor, although lots of other things can happen.

The tritone ii V is Dbm7-Gb7. I don't hear C7 as wanting to go to Dbm7. That's not to say that it can't possibly work -- just that it would require a very strong setting.

[rintincop]

Bar 4 I Can’t Get Started
Ab-7 Db7 | C

the book called “Pocket Changes” shows “all the things you are” in bar 6 as
| D-7 G7 Ab-7 Db7 | C... and the same type of thing again in bar 14

Also Autumn Leaves bar 5 and 6
A-7b5 | D7 | G- becomes
A-7b5 D7 |Eb-7 Ab7 | G-

[rpjazzguitar]

Bar 4 I Can’t Get Started
Ab-7 Db7 | C

the book called “Pocket Changes” shows “all the things you are” in bar 6 as
| D-7 G7 Ab-7 Db7 | and the same type of thing again in bar 14

Good reference! Usually it's a ii V in that bar, but the pair of ii V (regular and tritone) sounds good to me.

[2bornot2bop]

Here's another one. Find one that makes sense to you. Piano players tend to put in all sorts of crazy things and make them sound okay. Best keep it simple.

Attachment 77515

Here's a really good player but good luck copying that!

Doug plays respectable guitar too, although he’s much better on piano. Piano players make nearly anything work. It’s all in the keyboard.