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Old 12-16-2003, 08:54 PM   #44
pyr0r0ck3r
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Join Date: Dec 2003
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Lightbulb Circle of 4ths / 5ths, Basic Major Scale Theory, Chord Symbols, & Dom7 Chord

Circle of 4ths, that is, the next scale begins a 4th above the previous scale:

C -> F -> Bb -> Eb -> Ab -> C#/Db -> F#/Gb -> B/Cb -> E -> A -> D -> G -> C

Circle of 5ths, same as above, only the scale is a 5th above the previous

C -> G -> D -> A -> E -> B/Cb -> F#/Gb -> C#/Db -> Ab -> Eb -> Bb -> F -> C

If you notice, one is just a reversal of the other, therefore, in a Blues in C, the I IV V is

C F G

Basic Major Scale Theory

A Major Scale is not composed of 8 notes as much as it is composed of 2 sets of four, known as tetrachords. For example,

C D E F G A B C, the standard C major scale, is composed of the

C D E F
G A B C

tetrachords. When you look at the steps in betwen the notes, something interesting appears:
W = Whole Step
H = Half Step

C-----D-----E-----F
---W-----W----H---

G-----A-----B-----C
---W-----W----H---

The two tetrachords are tied together by a whole step, so the end result looks like

C-----D-----E-----F-----G-----A-----B-----C
---W-----W----H----W-----W----W----H---

Why is this important? Because it sounds the most "normal" to human ears. But why?

Play a from C to B and hold the B - you should notice that it feels incomplete, that there is something missing. Now play the C, and it will sound right - the B resolves or "pulls" to the C (note that there is a halfstep between C and B)

Now play C and play down to F and hold the F - you should notice the same thing, only backwards. Play the E, and you'll feel the resolution.

So what does this mean? That in the 2nd tetrachord, the resolution is from the 3rd to the 4th, and in the first tetrachord, the resolution is the opposite, from the 4th to the 3rd, or, in more general terms:

When playing, remember your two options for resolution are always (in terms of major scales): 7th (or derivation thereof, ie 15th) to tonic (either octave) or 4th to 3rd (or a derivation thereof, ie 11th).

Chord Symbols, what they mean

(C is root)

(Chord Symbol - Name - Which Notes of the Scale to Play - Scale Mode it belongs to (which degree the scale you start on))

C - C Major Triad - 1, 3, 5 - Ionian (1st degree)

Cmaj7 - C Major 7 - 1, 3, 5, 7 - Ionian (1st degree)

C6 - C Major 6 - 1, 3, 5, 6 - Ionian (1st degree)

C7 - C Dominant 7 - 1 , 3, 5, b7 - Mixolydian (5th degree)

Caug7, C+7 - Augmented 7 - 1, 3, #5, b7 - Phrygian (3rd degree) with a major third and a major 2nd (?)

Cm, Cmin, C- - Minor Triad - 1, b3 , 5 - Aeolian (6th degree)

Cm7, Cmin7, C-7 - Minor 7 - 1, b3, 5, b7 - Dorian (2nd degree)

Cmin6, C-6 - Minor 6 - 1, b3, 5, 6th - Aeolian (6th degree)

Cm7b5, C-7b5 - Minor 7 flat 5 or Half-Diminished - 1, b3, b5, b7 - Locrian (7th degree)

Co7, Cdim7 - Diminished 7 - 1, b3, b5, bb7 (6) - Lydian (4th degree) with a minor third (?)

Csus7 - Suspended 7 - 1, 4 (#3), 5, b7 - Mixolydian (5th degree) with an augmented 3rd (?)

See Previous Posts by Spastic for an explanation of Scale Modes

Dominant 7th Chord

In music, there is the basic idea of tension and release. One note/chord will build tension, then the next note/chord will release it. One of the most basic examples is the progression of the Dominant 7th chord (V7 chord) to the tonic chord (I). Whether arpeggiated or played as a chord, the effect is the same (for best results, play on a piano or guitar, or a similar chorded instrument):

G7
G B D F

resolves to

C
C E G

Theory on why this works:
*This is my theory, so it might not be correct*

The G7 chord contains the 4th of the C chord, so, therefore, when the G7 resolves to the C, there is a resolution from the 4th to the third. Also note that a G chord, without an F, will not pull to the C, but when the F is added, the pull is very noticeable.


Thats all for tonight, folks


Last edited by pyr0r0ck3r; 12-16-2003 at 09:02 PM.
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