I see that 3 minor 6th intervals can fit into the diatonic scale, but I never see any mention of flat 6th chords in any chord encyclopedia or diagrams etc...
So whats with these chords not making an appearance anywhere? I suppose one explanation could be that inverted seventh chords cover them so there's no need for any mention of flat sixth chords, but then using that logic would contradict how I always see major sixth chords written in every chord book/encyclopedia?
