On Sat, Jul 4, 2009 at 1:30 AM, Mark Polesky
<address@hidden> wrote:
Anthony W. Youngman wrote:
> I can't remember what it's called, but there's a third minor
> scale where the 7th can be raised or not. If it's going up to the
> tonic it's sharpened, and if it's going down, it's not. So in the
> scale of A (your classic minor) it goes:
>
> a b c d e f g# a g f e d c b a
The melodic minor. Though the 6th is also raised on the ascent.
a b c d e f# g# a g f e d c b a
I intentionally omitted it since it's so contextually dependent.
But I suppose you could specify it anyway:
The melodic minor scale smooths out the difficult-to-sing interval of the augmented second found in the harmonic minor scale. where the harmonic minor is full of harmonic possibility absent in the melodic minor form. The harmonic minor has a raised 7th degree in order to make the interval from the leading note (7th degree) to the tonic (the 1st or 8th degree of the scale a semitone.
This also enables a minor key to have a regular V - I resolution. without that raised 7th degree, the dominant 7th chord is impossible in the minor key.
Try, for arguments sake, having a final cadence in A minor without the raised 7th (it is g#). Without that raise 7th V-I or E7 - a minor doesn't exist, the chord progression would be em7 to a minor. Play ti and see what it sounds like. E7 to a minor makes a far more satisfying close. em7 to a minor sounds almost like ancient modal music. That is bascially why the harmonic minor scale came into use.
ascending:
i: min/maj7
ii: min7
III: maj7+5
IV: dom7
V: dom7
vi: -7
vii: -7
descending:
same as natural minor.
The chords that "belong" with degrees of any scale are triads. 4 note chords are chords with an extra third added on top, however by adding that fourth note a dissonant chord is created. That extra not added to the triad makes it a complex chord instead of a simple one. It is the triad that forms the basis of harmony in both classical and jazz harmony. In jazz harmony as in classical harmony, chords can eitehr be harmonically functional in that they imply some movement from one chord to another, or they can be simply there for colour purposes. The non-funtional chords require no resolution.
While all the notes of C maj 7th may be in the C major scale, not all of the intervals within that chord are perfect, major or minor (which contain no dissonances). The addition of the b in c major 7th creates dissonace from a completely consonant C major triad.
Another way of talking about this is to say that traids are far more stable than 4 note or complex chords. It is from triads that harmony is derived. 4 note chords are derived from 3 note triads.
Basically what I am trying to say is that talking about 4 note chords makes understanding harmony several orders more difficult than first coming to terms with the triads from which they are derrived.
cheers,
davidf
P.S. Nothing you have said is factuallly incorrect, its just you're talking about the basics in the most complex way you can. It really is easier to start by understanding the underlying triads than the complex 4 note chords. Begin with the triads built on each degreee of the scale, then move to understanding the iimplications of adding that fourth note.
- Mark