What is tridone chord subsititution and what's so bad about it?

It's really cheesy.

The most common usage is in a V-I combination except you play the V chord transposed a tritone.

eg... instead of G7 to C you would play Db7 to C.

ick!

Cheesy indeed!
Is there any logic behind this besides moving a tritone? I mean... it's not like a secondary dominant-like thing is it?

However cheezy, I like to think that anything can be made more interesting with a little bit of inspiration.

So, I'll try not to forget this, and use it for good...

I cant remember the priciples as to why it came about, I just learned about it when I was doing jazz theory back in the mid 90s.

Looks like it's sort of related to the Neapolitan Sixth.

The bII (below) is the Neapolitan Sixth (or Phrygian II). The second grouping of notes has the minor 7th thrown into the Db chord (so it matches Keef's jazz chord). The last grouping is probably close to the actual "jazz voicing." Sorry about the parallel fifth in the last one. Hey, it's jazz.

BTW:

Neapolitan Sixths stem from Minor-Subdominant harmony, and therefore do not belong in the "It's all about V-I, mo'fos" thread.

Here's a a better resolution for the Db7 chord:

Or if I really wanted to be disturbed about it:

Man...I never play anything in the key of V...the deepest I go is F. I heard that Steve Vai can play in the key of Z but that nobody can understand it except dogs and small woodland creatures.

Roivas, what program are you using to make those examples?