Originally Posted by: Whuneok I'm trying to get a global understanding of chord/scale relationships here
I've tentatively broken it down to these 3 concepts:

1 - formula of intervals determines the type of chord.
example:
Root + major 3rd + 5th = a major chord
Root + minor 3rd + 5th = minor chord
Root + minor 3rd + flatted 5th = diminished triad
Root + Major 3rd + 5th + Major 7th = Major 7th Chord
Root + 5th = "5 chord"
Etc

2 - root determines the key.

3 - If the root isn't the lowest note in the chord then it's an inversion.
Inversion is really just a matter of timbre preference... because the chord formula remains the same regardless?

is there another principle I'm missing that isn't subordinate to these three?
Are these three equal; or is one or more of these concepts actually subordinate to one of the other 3?
(I find that discerning hierarchy of concepts helps me to grasp material better)

thanks

Also you can add the major key chord formula which determines the specific chords in every key.

Majaor is

I ii ii IV V vi viidim

So in C Major we have C, Dm, Em, F, G(7), Am and B diminished.

Hope this helps :)