I have a problem with one issue.
In one key we have only two diatonic dominant chord,in the key of C it is G7
in progression V-I we could use ionian scale 'cdefgab' and other modes (dorian,phrygian etc).
Or mixolydian gabcdef.

E7 in harmonic minor progression V-i ( E7 |Am 'cdefg#ab' )


But we also have non-diatonic dominant chords in the key of C.
C#7 (triton substitution)
Ab7 (augmented sixth chord,three variants:german,italian and french)
D7 (secondary dominant)



Problem is: which scale is common for diatonic chords and non-diatonic dominant chord?
Which scale to choose in progression C#7 with any diatonic chord in the key of C
which in progression Ab7 with any diatonic chord
which in D7 with any diatonic chord.

There are some other non-diatonic dominant chords?
Between a)fourth and fifth degree, b)between second and third c)between sixth and seventh?

Then which scale is common for such a non-diatonic dominant chord and any diatonic chord in progression?


PS.But we also have several different dominant scales(exactly how many and which one to choose when?)

I don't think there is a standard, formula catch-all answer. I think what you play on non-diatonic chords totally depends on what the non-diatonic chord is and the context around it.

The good news (or bad, if you were looking for an easy answer) is that there are a fuckton of scales you can use over dominant 7ths chords. Mixolydian, Lydian b7, Altered Dominant, Symmetrical Diminished. Minor Blues. Major Pentatonic. Whole Tone. Phrygian Dominant. The list goes on. These can all "work" depending on context. My personal favorite these days is Dominant Pentatonic, which is 1-3-4-5-b7. Sounds like Indian music. Mahavishnu Orchestra uses it a lot. It's simple but you can get some cool repeating patterns out of it.

You could do the easy thing and just use the tonic Mixolydian scale on every different Dom7th chord but that might be boring or jarring, depending on your context. So maybe incorporating some of the other scales listed above (or other variants) where the various notes match the overall key of the song or lead you nicely into the next chord would be good places to try. All else fails, just start by soloing on chord tones and filling in the blanks using your ears. The typical jazz/fusion method says that the most powerful (and problematic) note movements lie in the half-steps of a scale, so organizing your notes to emphasize half-step motion during chord changes might be another route to experiment with.

I'm sure I learned more strategies about moving through secondary dominants and tritone subs in music school but I can't really remember. If you chords are moving fast enough, you might just be able to get away with some chromatic "outside" bullshit during some of the weirder changes.

Would you mind posting the chord progression in full, or even uploading a recording of you playing the progression? I wouldn't mind fooling around with it. I could use the practice too!

Ok, I don't have an instrument in front of me but maybe try this combination of notes:

F-G#-A-B-C#-D-E-(F)

the more simple way to write this scale would be starting from "A" so it's a Major (b6) type of scale like so:

A-B-C#-D-E-F-G#-(A)

However, the "A" note will clash with the C#7 chord. The F might serve as a better tonal centre for a melody because it's the only common note between the two chords. However, it's going to be a weird-sounding scale so using this for an extended period of time might sound a little alienating, so your mileage may vary.

I'm just looking at an online keyboard app here and I can see some interesting possibilities here. This scale would give the Dmin chord a Melodic Minor sound and you could do some cool b9 diminished arpeggios during the C#7 chord. Ultimately, your best ally will be your ears and how much you're willing to experiment.

Hmmm...here's how I did it.
Chord C#7 = (c# f g# b)
Dm = (d f a)

Now we can arrange all notes in order c# d f g# a b
One note for full seven-note scale is missing but we can add note 'e'.
Then we get a scale d e f g# a b c# which is "dorian sharp 4 and 7"


Anyway,we have another variant of progression

Haha I went through a very similar process to get my answer. Yours would probably work nicely since it's resolving to the Dmin anyways.

This is a fun thread! I'll look at the other progression when I have some more time--it's a lot more involved hehehe