The fretboard can be a complicated terrain to navigate. Many notes can be played at the same pitch in multiple positions, and the third and second strings are tuned a major 3rd apart, whereas the rest are tuned to the interval of a 4th. With this in mind, the is a useful tool to help the fretboard make a little more sense.
This system is based on any chord being able to be played in five different positions, based upon the five main open-position major chord shapes of C-A-G-E-D. In essence, each one of these chords can be moved up the guitar neck, most commonly utilising the first finger to barre across the fretboard. Most guitarists are familiar with the E and A shape barre chords that are commonplace in blues, pop and rock.
Full barres using the C and G shapes are a little less popular in contemporary music, but are prevalent in . These shapes can be trickier play, but they do have something different compared to the E and A shapes. This is that they allow for the notes of chords and to be played in sequence.
Take the open C major chord. The intervals in ascending order from the fifth string up to the first are: root, major 3rd, 5th, octave and 10th (essentially another major 3rd stacked an octave higher). This shape, along with the open G chord, are therefore constructed in a logical fashion, whereas the open E and A shapes are rather more disorganised – although this makes them perfect for powerchords, for example.
Our final shape is the D shape, based upon the open D c.