Circle of fifths

                         C 

                     F       G

                       

                 Bb              D

              Eb                    A

                 Ab              E

                     Db      B

                                              Gb

With the exception of the tuning from the third to the second string (G to B) the guitar is tuned in five step intervals. For example, when tuning by ear you play the fifth fret on the sixth string (Low E) to get the same pitch as the open 5th string (A). In music theory this is called a Unison. What is cool about the guitar is that this interval is the same no matter where you are playing on the neck. For example the eighth fret on the Low E is C. So is the third fret on the A string. Unisons are always five frets apart. What this demonstrates for us guitar players is that the shape of any interval remains the same regardless of the notes or position across most of the guitar. So once we can play intervals that are a fifth apart (seven steps) the circle of fifths should be easy. 



Notes occuring in Circle of 5ths are X , X+5frets of X + 2W+1S
W=whole tone, S=semitone
eg. G + 5fret = C
C + 5 frets = F and so on.......
D+5 frets = G............
So consider chord theory, major chord in C has CEG.......so G is 5th note
Similarily G chord has GBD...........D is 5th note in G scale