Bitonality with minor sevenths

Finally, we should consider triads with minor sevenths. I’m going to tell you that, as far as I know, there aren’t any. I don’t use any. Why is that? Take C minor7 and the scale that goes with it - the Dorian mode then you remember with minor scales the notes all tend to come in on the same footing. So we can make triads out of those notes from the scale but they’re not actually, kind of, going to change the character of the underlying chords. Let me be precise. I’m just going to take triads when the notes come from the Dorian mode. So first of all C minor triad obviously doesn’t give you anything new.

That’s quite a nice sounding chord it’s all thirds. That’s D minor triad, but because it is notes from the underlying scale I don’t somehow see it as being a different chord. Similarly that’s quite consonant E flat major triad. F major triad G minor triad This one’s a bit unusual because this is a diminished - because there’s a minor third from A to C and a minor third from C to E flat. Then B flat major triad. So you can use all those sort of triads.

In that sense there’s no new theory or no no new chords for minor sevenths. You could try using some of the other major triads and minor triads, but I don’t think you’ll find that you get anything that sounds very good. Anyway, I don’t use them if they exist.