I have been using this method to teach my guitar students for the past 8 years. I find that in the beginning when they are learning theory related to the guitar or bass its best to remove the circle of fifths to the equation till they can get a grasp on the basics of scales and modes.
Below is a post I have made on a few forums regarding the subject. I hope it help some of the newer players understand how Scale & Modes work in relation to guitars.
Theory is really simple actually. This is going to be a very long post, so give me an hour or so to get it all together for you
IF YOU DONT UNDERSTAND THE Root - 3rd 5th thing just keep reading. It will become clear
Applying music theory to song writing.
This is a very indepth subject but I am going to break it down to its core elements as it comes to song writing and the guitar in general. Music Theory is probably the monst important thing you can learn as a musician. The ability to use expanded chords and voiceings in your songwriting can add depth and dimension to even the simplest of riffs.
Part 1: The Theory Of Music:
All western music is based off of the 12 Note Chromatic Scale:
The foundation for most western music is based off of the C Major Scale. The C Major scale is the only Major Scale which contains no flats or sharps. Everyone knows the C Major scale, if you sing Do, Re, Mi .... Thats the C Major scale.
The notes of the C Major Scale are C - D - E - F - G - A - B - C
We are going to use the C major Scale as the base of this lesson.
Part 2: Building Chords:
To put it in its most simple form Major chords are made up of the Root 3rd and 5th of any major scale. So if we use the C Major Scale as the base of this we end up with the notes C - E - G. If we play the 3 of these notes together as a chord you get a C Major Triad.
Minor Chords are built using Root flat3rd and 5th of the Major Scale. So if we use C Major as a reference we get C - Eb - G. If we play the 3 of these notes together as a chord you get a C minor Triad
Chord building and knowing how chords work is invaluable for a guitarist / songwriter. It allows you to build and create chord progressions, arpeggios, and give you the tools to create different moods and tensions when soloing over a chord progression by using Modes (more on modes later)
To put this into practice and songwriting in a metal context, one thing you can do is have the Guitar player just playing standard power chords (root and 5th) and you can have a clean guitar playing the Triads or the "tension" below it. The tension is what gives a chord its "color" wether its Major minor or diminished, tension notes are your 3rd, 4th, 6th, 7th, 9th, 11th and 13th.
So guitar one would play C5 (C and G) and the clean guitar would play a C Major Triad over it. This would give you a very happy sounding riff. Alternately you can do the same with Minor chords. You can have one guitar play C5 and you can have the other guitar playing a C Minor Triad.
So to put it simple have the main guitar play a Power Chord and have another guitar play the tension on top of it to give the riff its color or mood.
Guitar one plays C5 (C and G) and guitar 2 plays Eb, and G, the Eb of guitar 2 gives the chord its minor characteristic. Guitar 2 could even play Eb and C and you would still get the minor tonality. Experiment with different chords and see what sounds best to you.
a.) Using octaves to your advantage:
An octave is 2 notes that are separated by 12 semi tones (half steps). For example, playe a C on your A string (3th Fret) then play an A on your G String (5th Fret) these notes are exactly 1 octave apart.
You can use these octaves to your advantage to make a riff more interesting. So lets take that same C5 chord we played earlier and have the 2nd guitar play a slowly arpegiated chord using C E G one octave higher. This can add some depth to a simple riff.
b.) Chord Harmony
Using chord harmony is another way to make a riff cool. Say we have 2 guitars, Guitar one plays a C Major Chord in the 3rd position (your basic C major chord). The 2nd guitar can play an A Minor chord over that and harmonize the part using music theory!
How is this possible?
Well this gets into the deepest part of music theory. Scales and Modes
Part 3: Scales and Modes
The easiest explination I can give you of modes is they are scales that are built from different parts of the Major (or minor sometimes) scale. This can get very confusing so I am going to build you a small chart so you can see how it works.
The modes follow a specific order: This order NEVER changes
If we apply each note of the major scale to each of the modes based in C we get.
C Ionian (Major scale)
D Dorian (Minor)
E Phrygian (Minor)
F Lydian (Major)
G Mixolydian (Major)
A Aeolian (Minor Scale)
B Locrian (Diminished)
Each note also get asigned a "degree" in the scale. This is very useful for chord progressions. ir would look similar to this.
C - 1 (Root)
D - 2 (2nd)
E - 3 (3rd)
F - 4 (4th)
G - 5 (5th)
A - 6 (6th)
B - 7 (7th)
So lets put it all together:
Ionian (Major) - C - 1
Dorian (Minor) - D - 2
Phrygian (Minor) - E - 3
Lydian (Major) - F - 4
Mixolydian (Major) - G - 5
Aeolian (Minor) - A - 6
Locrian (Diminished) - B - 7
So based on this we can build chord progressions based within the key.
Lets use a ii-V-I (2 - 5 - 1) progression for this example.
So if we take the 2 chord (D minor) the 5 Chord (G major) and the 1 Chord (the C Major) and play them in succession we get a ii - V - I chord progression. If we expand on this into soloing over this progression, you can play D Dorian over the D minor chord, G Mixolydian, over the G Major Chord, and C Ionian, over the C major chord
There are a million other options but for now to keep this "SIMPLE" we will just name those.
But how do you know what a D Dorian or a F Lydian Scale is?
That my friends is the most SIMPLE part of Music Theory. If you know the notes of the Major Scale you know ALL of your modes. The easiest explination is a Mode is a Scale staring on a Degree in a Major scale and continuing that scale through its octave. CONFUSING I KNOW, but onece you SEE it you will understand. Look at the example below:
C - D - E - F - G - A - B - C ( C - Ionian Mode )
D - E - F - G - A - B - C - D (D - Dorian Mode )
E - F - G - A - B - C - D - E (E - Phrygian Mode )
F - G - A - B - C - D - E - F ( F - Lydian Mode )
G - A - B - C - D - E - F - G ( G - Mixolydian Mode)
A - B - C - D - E - F - G - A (A - Aeolian Mode)
B - C - D - E - F - G - A - B ( B - Locrian Mode)
See the Pattern? Make Sense?
If you play all the notes of a C Major Scale starting from D and playing through D you get the D - Dorian Mode, If you play all the notes of a C Major Scale from A to A (octave) you get the A - Aeolian Mode.
See how easy that is
Part 4: Expansion into other keys
You can use the above examples starting from any Major scale. Lets use F major for our next example. The note of the F Major Scale are F - G - A - Bb - C - D - E
So that gives us:
Ionian (Major) - F - 1
Dorian (Minor) - G - 2
Phrygian (Minor) - A - 3
Lydian (Major) - Bb - 4
Mixolydian (Major) - C - 5
Aeolian (Minor) - D - 6
Locrian (Diminished) - E- 7
So if we have a progression that is A minor, D minor and F Major what modes should we play over each chord?
(scroll down for answer)
If you said A Phrygian over the A, D Aeolian over the D and F Ionian over the F major then you got it right! THATS MUSIC THEORY!!!
Ok guys I have to get back to work but thats the basics of how music theory works
I will explans on 9th's 11th's and 13ths later .... I just have to get back to work
Quickly, if you keep counting into the next octave the 2nd becomes the 9th and so on ....
Great first contribution.