In his method, Fernando Sor advocates a way to practice the notes along each string. In my Free eBook on learning the notes on the guitar (available on the free stuff page) I describe a way to learn the notes by memorizing the naturally occurring half steps and the notes on two strings and then relating those two strings to the rest of the fretboard.
Sor’s method offers a very good continuation of what I describe.
First: Constructing Major Scales
The cool thing about scales is that they always maintain the same relationship among the notes no matter what key. That is, to be a major scale the arrangement of whole and half-steps is always as I describe below. The numbers represent notes in a scale (called scale degrees). WS=whole-step or two frets. HS=half-step or 1 fret.
1 (WS) 2 (WS) 3 (HS) 4 (WS) 5 (WS) 6 (WS) 7 (HS) 8 (same notes as 1, octave higher)
If you think in terms of of the C major scale:
C (WS) D (WS) E (HS) F (WS) G (WS) A (WS) B (HS) C
This arrangement of whole and half steps is the same for any major scale.
Sor describes treating each open string first as the tonic of a Key area. Take the sixth string, E, for example. If it’s the first scale degree (the tonic), we’d be in the key of E. We’d then run the E major scale up the sixth string:
E F# G# A B C# D# E
After finding all those notes on the sixth string, we’d then treat the open E as the second scale degree. To find it’s tonic we’d have to go down a whole step (remember the distance between the second scale degree and the first is a whole step). We’d be in the key of D, and we’d run the D Major Scale from E to E.1
E F# G A B C# D E
E can then be treated as the third scale degree of C major, and run the C major scale from E to E on the sixth string:
E F G A B C D E
Then it can be treated as the fourth Scale degree of B major, and so on until E is treated as every scale degree.
Here’s a PDF (Ex. 18) with all the combinations for each string.2
Why Practice This Way?
This method could add some interesting variation to learning the notes. It also lets the student practice major scales in a more theoretical sense — especially if the student, instead of looking at the PDF linked, figured out everything on her own.
1 Sor is describing running each of the modes — Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian and Locrian — using the open string as the tonic for each mode. He doesn’t say this, however. It’s probably easier to think of it in terms of a major scale starting on different scale degrees (a way modes are commonly described anyway).
2The PDF linked is taken from this version of Sor’s method by Frank Mott Harrison. This “translation” is an english adaptation (and expansion) of the original English translation by A. Merrick. The exampled I pulled out, however is the same in both versions. Brian Jeffery dismisses the Harrison version as “a work of small value” (source). The A. Merrick translation is published by Tecla and Brian Jeffrey in facsimile. However, Dover (aff. link) offers the Merrick translation for much cheaper.