What helped me understand it a bit more is the fact that the original chord (the V7) and it’s tritone substitute have their 3 and 7 swapped around. The G7 has B (3) and F (b7), where the Db7 has F (3) and B (b7). Since it’s generally the 3 and 7 determining most of the “quality” of the chord, this allows for a relatively seamless substitution. Feel free to correct me if I’m wrong, I’m not a pro, just soaking up theory and trying to apply it in practice.
Tritones are equidistant when inverted (A4 d5), so this is a pretty logical conclusion to make, and of course it’s why bII can serve as a V or even as a way to approach V in a different context (Neapolitan chord)
@@negativize_11 yes, the principle of leading from a semitone above can be found for example in a Stevie Wonder cadence to C: F - Ebmaj7 - Dbmaj7 - Cmaj7, or in the Tristan chord which is built on Dm/F - E. Specifically the Neapolitan is based on Am - Bb/D - E7 - Am (Mozart) or Am - Bb - E7 - Am (Chopin). In both cases the Bb moves to E first before resolving to Am.
The Db chord shouldn't be a dominant 7? (Db - F - Ab - Cb). Db b5 b7 sounds good but every example I've seen of tritone substitution changes for another dominant 7 chord, not just the bass note.
Yes, it’s common to call this chord “Db7’, but in reality the B note moving to C stays. It’s not a Cb note. It’s still the same leading to B moving to C. When you think in voices and counterpoint you realize that it’s just the bass note changing its course from moving G - C to Db - C.
@@dr.guyshkolnik_composer Thank you very much! It wasn't the B (Cb), but the G the note that didn't fit to me in a Db7 (I thought it should be an Ab), but now I see it's altered (Db7 b5; I spelled incorrectly on my first comment)
Edit: But his approach is different.The G stays so the shift is from the D note to Db note. His is Db7b5 not the usual Db7. BTW Db7b5 is equivalent to G7b5/Db. It works.
@@dr.guyshkolnik_composerDoes the Db7b5 work better than the usually seen Db7 because it retains the G-C note movement? It might be time for a new series :))
@@apparentlybrian it depends when. Don’t think I terms of “out of the box” chords that will work every where. The key is to think more in terms of voice movement and less in terms of chords