1. You must know all seven positions when playing a major scale.
2. You must memorize the degree of each mode. Here are the definitions:
1st degree = Ionian
2nd degree = Dorian
3rd degree = Phrygian
4th degree = Lydian
5th degree = Mixolydian
6th degree = Aolean
7th degree = Locrian
3. You must memorize how the major scale is constructed, ie with intervals.
Here's the formula:
R = root : W = whole step : H = half step
Formula = R W W H W W W H R
So, to construct the C and E major scales you do the following:
R W W H W W W R R W W H W W W R
C D E F G A B C E F# G# A B C# D# E
Pretty easy eh!
OK, now this part may be confusing, but I'll try to elucidate.
Let's say that you want to construct the D Dorian Scale. Start by identifying the root note somewhere in the middle of the neck of the guitar. The number at the top of the virtual fretboard, below, indicates the fret number. The X's indicate the note associated with the scale. The R's indicate the Root.
3 4 5 6 7 8
E| | X | | X | |
B| | X | | X | X |
G| X | | X | R | |
D| X | X | | X | |
A| X | X | | X | |
E| | R | | X | |
Hopefully, you will recognize this particular pattern. Now to obtain the Dorian scale, let's locate the 2nd degree of the major scale formula. Remember, the formual is RWWHWWWH!
So, starting at the root, just count up to the 2nd degree.
1 2
R W
And we find that we have to move our entire scale pattern, above, DOWN the fretboard by one whole step! So, here's the D Dorian Scale:
1 2 3 4 5 6
E| | X | | X | |
B| | R | | X | X |
G| X | | X | X | |
D| X | X | | X | |
A| X | X | | R | |
E| | X | | X | |
Notice that the Root notes and position have changed, but the pattern has not! Now, the reason for knowing all seven positions is so you can link all of the different positions to form the scale over the length of the fretboard.
Let's try another, say D Lydian. Let's find the interval determination by counting the intervals from the root to the 4th degree (Lydian).
1 2 3 4
R W W H
And we find that we have to move our entire scale pattern DOWN the fretboard by two and a half steps!
Hope this helps out.
