ESSENTIALLY, these‘deluxe’versions of Minor 7th chords can add a little class to any chord progression – maybe not in heavy rock, but even then, these added notes can inform your melodic choices when soloing over the heaviest of metal… This is an enormous and fascinating subject, but we’re taking it on a small chunk at a time, though many of these principles hold true in other musical contexts too, so take your time to fully absorb the info here and you’ll start noticing it in use in all sorts of contexts, be that vocal melody lines, solos or chord progressions.