PG Music Home Forums General Discussion Woodshedding - Learning to Play! Question about minor II V I's

"Could I give context..."

Well I am not the man for that job really. I simply opened a couple of books on II VI I's and got this as quoted above. Aebersold was one as I recall. Please see below though...

Although I can blagg these chords quite easily, that's not the same as really understanding and I want to achieve this understanding, make it crystal clear.

I have been doing a lot of work on these changes. I needed to brush up my diminished and altered chords which were a bit stiff, an ideal opportunity seems to be these minor II V I's

It seems to me to boil down to this. The II chord is a half diminished. If the piece were a 'natural' minor key, then this would make the II chord a locrian mode which has a flat fifth.. There are a couple of options that come to hand - the diminished scale; you can take stacks of minor thirds on that, this features a major six tone on the fourth note built from the root.
The second option id to raise the second.

So in terms of which minor scale is implied by the two chord, if you played a 'straight locrian, it has a minor third, dissonant b5, and a b7. These all fit 'natural' minor modes.

If you use the diminished in m3rds starting from root, the this gives a leading tone to the minor key (assumed) and would suggest either a melodic minor, or harmonic minor key signature (at this point).

Moving to the 5 chord, well this is where almost anything goes. It is possible to play a minor seventh chord here, and this would be the strict spelling of the 'diatonic' or 'natural minor mode'. This is a bit limp.
SO, the first step is to slip in the 'illegitimate' natural third. This converts the chord to a standard dominant seventh (myxolydian) chord, but this still sounds a little weak. I believe that adding the raised fifth of the 5 chord e.g. talking in C the D# gives you a note that is enharmonic with the minor third of the key sig, if you did not do this, and left a straight myx G7 chord, then the perfect fifth would sound a D the second note of C minor key sig. This is OK but not so effective as the raised fifth, which as the minor third of the key, sounds the mission critical tone.

with me so far....


So we are looking at the V chord of C minor II V Is. We understand the root, the third (better raised) and the fifth (also better raised). What about the seventh tone.
To me, this note is very disputable. If you were to simply play a (dull) 'diatonic modal line' then this would give a flat 7 to the chord. This is the fourth of the key (some old jazzers called this note the avoid note) whislt this was never completely true, sounding (perfect) fourths of the key signature, does not do too much to establish the key. Don't get me wrong, it can happen of course,. The fourth is happy enough as a passing tone or in other special cases.
The alternative is a raised fourth, sounding a major 7th of the chord, which is also the raised fourth of the diatonic key signature. This is obviously a feature note, like an elbow sticking out.

Seems to me that the 5 chord can be subbed, rewritten in a lot of ways, these being just a few of them..


Then there is the I chord:

Well what exactly is the one chord? Is it a natural minor, a melodic minor, or a harmonic minor?

My observations on this is that everything is fine up to the perfect fifth. But then what?
I have no idea really, perhaps there are no rules, its just dependent on the piece. Some say Jazz favours the melodic minor. What it boils down to is this, taking C for example.

You can take the first five notes until the perfect fifth for granted then you can go:

b6, b7 (AKA natural minor)

Maj 6, major 7th (melodic minor)

major six, flat seventh (dorian)

or..

b6, major 7 (harmonic minor)

then octave.

You can use chromatic passing tones, but we leave this aside for now...

Now it is true that minor keys are more forgiving than major, but that's really a get out of jail free clause. There are possible serious clashes.

The trouble is, if you play a flat 6 where everyone else is playing a major six. that's a Big NONO! Same with playing major and minor sevenths together (though you can use a major seventh as a passing tone between b7 and octave. Basically the wrong kind of seventh is a car crash with the band.

So, what to do?

I am not sure at all. Obviously depends on the context, but how do you prepare the way?

Seems to me that the 5 chord can be subbed, rewritten in a lot of ways..


Still puzzling over this...


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