Any Theory Gurus help with this?

[Bellycaster]

Just been reading a couple of pages I found on Diatonic sequences and Chord Progs. I understand most of it but one little part is glossed over and not explained(unless I missed it).

The passage below is from one page regarding the Harmonic Minor Scale.

And here is a link to the page too.


http://www.ultimate-guitar.com/lesso...s_part_ii.html



Now, if we use strictly the natural minor scale, we get this:

i, iio, III, iv, v, VI, VII, i. For the most part, this is okay, but there's one big problem, and that problem is the minor v chord. The reason the V chord works as a dominant chord is because of the half-step resolution that it brings to tonic. This is much easier seen than explained. So in F major, the I chord is F major, and the V chord is C major. C major contains the notes C E G, and F Major contains the notes F A C. Both chords contain the note C, from G to A is a major second, but E to F is a half step, and its resolution is very important to the harmonic context of your song. That E is called a "leading tone" because it feels like it "wants" to resolve, or lead, us to that F. Now if we go in F minor, the i chord contains the notes F, Ab, and C, and the v chord contains the notes C, Eb, G. Now while there is a half step present from G to Ab, this does not have the same sort of pop that the 7-1 resolution has. So how do we solve this? We use the harmonic minor scale to make the V chord major, and we get C E G. Now, we have that important E to F (7-1) resolution which is necessary. This is why the harmonic minor is called "harmonic" minor, because it is used to create "harmony."
Now if we used all the harmonies found in the harmonic minor scale, we get this:
i, iio, III+, iv, V, VI, viio, i. This is perfectly fine, but I should warn you that resolving that augmented III chord is no fun at all. Its also very rarely found in conventional music, but more power to you if you want to experiment with it.




What I don't get is that the guy here is just explaining that the V chord is changed to Major to acheive the resolution required, but did not explain why the III has changed to III+(augmented) and the VII has changed to viio(Dim)

I understand changing one thing may lead to other things also having to change, but I would have liked him to have explored this a while.

BTW I am only newish to delving into this sort of stuff, so your replies may need to be idiot freindly

Cheers.

[SevenSharpNine]

The harmonic minor scale and the natural minor scale are mostly the same, but the harmonic minor scale has a raised 7th. This means the 7th note of the scale is raised by a half step.

The Natural Minor Scale in C is: C, D, D#, F, G, G#, Bb

The Harmonic Minor Scale has a raised 7th scale degree, so the Bb becomes a B.

When you build chords from a scale, you take each note and stack thirds on top of it. So your first chord starts on C. The third above C is D#, and then the third above the D# is G. This makes the notes of your first chord C, D#, G, or C minor.

To find your next chord, you use the same process, but starting on the second note, or D. Stacking thirds gives you D, F, and G#, or D diminished.

You continue with each note in the scale to get your chords. However, because we raised the Bb to B for the Harmonic Minor Scale, any chord that normally has that Bb is going to be changed.

For example, in the Natural Minor Scale in C, the third chord begins on D# and contains the notes D#, G, and Bb. These notes together make a D# major chord. D# is the root note, G is the major third, and Bb is a perfect 5th. However, in the Harmonic Minor Scale, we don't have a Bb, we have a B, so we have the raise the Bb to a B. This means we have a raised 5th in the chord, which makes it an augmented 5th, and makes the chord a D# augmented chord.

[jalapeno]

I can't remember which way round, but in classical music you go up the scale with the Melodic Minor, and back with Harmonic Minor (or vice versa). Jazz doesn't really use Harmonic minor at all.

[octatonic]

I can't remember which way round, but in classical music you go up the scale with the Melodic Minor, and back with Harmonic Minor (or vice versa). Jazz doesn't really use Harmonic minor at all.

In classical* music you mostly play the melodic minor by ascending with a raised 6 and 7 and descend with the natural minor.
So A melodic minor would be played as A B C D E F# G# A (melodic minor) and then back down as A G F E D C B A (nat minor).
There are a few exceptions to this though.

Plenty of jazz musicians use the harmonic minor, as well as the modes.
Al Di Meola uses it loads.
It is of particular use in minor ii V I's.

*Classical is all western art music, not just the 1750-1820 style between Baroque and Romantic.

[clarky]

this harmonic minor stuff comes from a thing called a 'perfect cadence'
a perfect cadence is like the musical equivalent to a full stop.
a perfect cadence is always chord V to I
in a major key both chords V and I are major
example in E: I = E, V = B
so a perfect cadence in E would be
E to B

in a minor key, both chords I and V are minor
so in the key of Em, your cadence would be: Bm to Em
the problem is that this don't sound very 'final' given that it's supposed to be like a full stop..

solution...
in a minor key, during a perfect cadence, chord V is modified temporarily to a major chord..
so V to I in the key of Em is now B to Em
sounds nice and final... prob solved...

or is it...

the notes in the key of Em are: E, F#, G, A, B, C, D
we know that the diatonic chord V created by this scale is Bm - B, D, F#
during the perfect cadence in the minor key, chord V is modified to a major chord..
our Bm is now B, which is: B, D#, F#
so when this modified V [B in this case] is sounding, the scale also needs to be modified to avoid that clash between the D ins the minor scale and the D# in the modified chord V.
so we get a new scale
E, F#, G, A, B, C, D# - which is called [in this case] E harmonic minor because it's harmonically adjusted to sound right when this modified chord V is sounding.

notice that the interval between note 6 and note 7 is large...
it's a sharpened major 2nd [which sounds just like a minor 3rd]
choirs in the 17th century didn't like singing this huge interval.. especially in the ascending direction..
solution.. make the interval smaller...
this is achieved by also sharpening note 6
so our E harm min scale now becomes this..
E, F#, G, A, B, C#, D#
the large interval between the 6th and 7th notes [the sharpened maj 2nd] is now reduced to a maj 2nd]
much nicer to sing [for choirs] cos it's like the tail end of a major scale
this adjusted harm min scale [for melodic reasons] is called the melodic minor
like the harm min scale, it is only ever used when the music is in a minor key and during a perfect cadence when chord V [having been modified to a maj chord] is sounding.
the difference though is that the mel min scale is only used when the melody notes are rising [ascending]
and so it's called the melodic minor ascending scale..

note - this is classical harmony.. jazzers took these scales and did a whole pile of different things with them...

[clarky]

The Natural Minor Scale in C is: C, D, D#, F, G, G#, Bb

just a little thing regarding your music grammar

this: C, D, D#, F, G, G#, Bb cannot exist

you must have one of every note in a diatonic scale and they cannot be duplicated..

it should be this: C, D, Eb, F, G, Ab, Bb

[Bellycaster]

Thanks Clarky. I am familiar with the alteration for perfect cadence and the V chord, but that's not the question. What I highlighted in Bold is the confusion. Here.

Diatonic Sequence In Natural Minor

i, iio, III, iv, v, VI, VII, i

Diatonic Sequence in Harmonic Minor

i, iio, III+, iv, V, VI, viio, i

You'll notice that the III has become III+ and the VII has become viio. Why have these altered as well as the V?

Your reply was helpful too, but my confusion lies with the above. Maybe because the V chord has changed then that is the reason the III and VII have changed too,like, if you change one thing in a sequence, things around it will have to change too.

Cheers.

[octatonic]

Why have these altered as well as the V?

Because you are harmonising the scale.

[Bellycaster]

Thanks. I guess the best way would be for me to PLAY each sequence of chords and listen at why it sounds like whatever it sounds like. It just confused me because only 1 note/chord has changed, but it changed chords of notes that had not been altered.

[clarky]

now we're into Jazzer territory
a Jazzer will not restrict the use of harm min and mel min asc to just a perfect cadence in a minor key when the modified chord V is sounding...
to a Jazzer, these scales are just like any other and so can be used without limitations..
and therefore these scales can generate chords [hence all that ugly upper and lower case crap that is common charting in the USA]

Diatonic Sequence In Natural Minor
i, iio, III, iv, v, VI, VII, i
example:
The key of A minor: A, B, C, D, E, F, G
if you generate chords from this scale you get
Am: A, C, E = i [lower case means minor]
B diminished [Bm b5]: B, D, F = iio [where ii = chord 2 is minor and o = diminished 5th]
C: C, E, G = III [where upper case III = chord 3 is major]
Dm: D, F, A = chord iv is minor
and so on

Diatonic Sequence in Harmonic Minor
i, iio, III+, iv, V, VI, viio, i
The scale of A harm min: A, B, C, D, E, F, G#
if you generate chords from this scale you get
Am: A, C, E = i [lower case means minor]
B diminished [Bm b5]: B, D, F = iio [where ii = chord 2 is minor and o = diminished 5th]
C augmented [C #5]: C, E, G# = III+ [where III = chord 3 is major and + = augmented 5th]
Dm: D, F, A = chord iv is minor
and so on
and this viio means that chord 7 is diminished
which following our example in A harm min = G#dim [or G#m b5]