TAC Family Forums

Not sure about a chord matrix but as Loraine said in different words is that a 7th chord (dominant 7th chord being the full correct term) is just a regular (3 note) chord (the 1-3-5 degrees) with an added 4th note which is the 7th scale degree but flattened one half step. If it were the regular 1-3-5-7 four note combo we’d have a “major 7th chord”.

I hope that helps!