IMO< the best means of playing any scale over two octaves is too abide by four basic rules;
* one finger per fret
* shift up the neck with your first finger
* shift down the neck with your pinky
* only position shift over a tone interval, never a semi-tone
Where in the scale you put the shifts depends on what position you want to end up.
G Major over two octaves to end up with your second finger on the G on the A string - ready to play G Major in the octave - would be
E string
G - 1st finger
(shift)
A - 1st finger
B - (3rd finger)
C - pinky
A string
D - 1st finger
(shift)
E - 1st finger
F# - 3rd finger
G - pinky
D string
A - 1st finger
(shift)
B - 1st finger
C - 2nd finger
D - pinky
D string
E - 1st finger
F# - 3rd finger
G - pinky
Alternatively, you could play all the way up to the E on the D string, then shift your 1st finger up a tone to the F# and play in that position up to the D on the G string, then shift your 1st finger, again up a tone, to the E F# G.
Personally, I find playing G A B on the E string in one position is too much of a stretch to give you a real solid feel to the notes. I prefer to make as small a stretch as possible.
The trick is learning all scale in as many positions as possible, constantly using the rules above...
For the major scale
* on 1 string starting on the 1st finger
* on 2 strings starting on the 1st finger
* on 2 strings starting on the 2nd finger
* on 2 strings starting on the pinky
* on 3 strings starting on the 1st finger
* on 3 strings starting on the 2nd finger
* on 3 strings starting on the pinky
I cant think of any more, but note that you never start on your 3rd finger (because the 2nd of the major scale is a tone from the root).. if you were playing phrygian mode you would need to pratice starting on your 3rd finger rather than your 2nd finger.
It's lots to work on, take it step at a time. I can thoroughly recommend 'a key per week'
