In a practical sense I daresay I can work this out for myself, but I'd like to know what the "proper" way of doing this is.
Suppose I'm playing in a particular mode. My example is E phrygian. I want a chord that is going to bring me back to the tonic. In E major, the strongest pull is from the dominant, the V chord, B7 > E. In E minor, the usual thing seems to be to "cheat" a bit and play a B7 anyway, even though, strictly speaking, the v chord is minor and B7 is out of key.
In E phyrgian, the diatonic V chord is B half-diminished, which has a very strong pull sure enough, but it pulls us to C, not really back to the tonic Em.
Should I play a B7 anyway? Or do some other thing? (Meaning "should" in the sense of "what is the most traditional?")
To my ear, the obvious chord in E phrygian that really, really wants to come back to the tonic is the II chord, F. But what does the theory say?
More broadly, and without asking for an epic-length essay of an answer (well OK, maybe I am) how about the other common modes?
Comments
In that context I think of the B7 as being part of the E harmonic minor scale.
You can also “cheat” as you put it, and deploy a V or a V7 in any other scale - minor, dorian, phrygian, mixolydian, as well as any other non-diatonic scale you fancy playing in, like Hungarian major for example, in fact, whatever scale you like. Even though all those scales strictly speaking call for a minor 3rd on the dominant. Basically whenever you want to return to the tonic chord, you can come off a V7 if you fancy. That’s just making music. There is NO RULE that states you have to, or even you should, stay within the diatonic notes. In fact I can’t think of a single classical piece that does!
Supportact said: [my style is] probably more an accumulation of limitations and bad habits than a 'style'.
Also, Em and Cmaj7 are basically the same chord. As is the Bdim and G7.
Less dominance....