Does anyone have any good tips on chord substitutions in this idiom?
Advance warning: I know very little about jazz theory so some of what I say below may be incorrect.
I noticed while working on "Blues in Minuer" in Gm that when I go to the Cm6 (IVm6) that chord has a tritone in the m3-6 note pair -- the same interval shows up in the VIIm6, in other words F#m6 (2x12xx). So instead of 2 bars of Cm6 it sounds quite nice if I play 6 beats of Cm6 and then 2 of F#m6 and then back to Gm6.
Would that be a typical GJ sub?
Similarly, when I go to the V7 chord (D7) there's a tritone interval between F# and C. The same interval is in a G#7 but that doesn't sound right resolving to the tonic minor 3rd. The tritone is also in an Ebm6 (x3434x). This sub sounds quite nice, again for the last 2 beats before resolving back to the tonic.
Again, is that something that seems like a reasonable sub for this idiom?
Any tips on books or websites to help me understand which subs I might use where would be appreciated...