The hollow circle in the diagrams is the root. The shapes suggest various ways for you to visualize the basic pattern of the pentadominant scale shown by the Dots. The fretmap that best demonstrates the symmetry of the pentadominant scale is the Crosses.
|Clock||Dots||Broken Diagonals||Steep Diagonals||Crosses||2 times 2|
The extraordinary symmetry of the pentadominant scale results in highly regular patterns when it is mapped to the fretboard of the M3, even more so than the pentatonic and hexatonic scales. Four out of the five notes fall on two out of four indices so one index is not used at all (one fret out of every four does not contain a note from the pentadominant scale). The Broken Diagonals show that you can go from the 3rd up to the b7th in two steps of three semitones. The Steep Diagonals highlight the interval of six semitones (between the 3rd and b7th) which does not occur between any pair of notes in the pentatonic and hexatonic scales. The Crosses show you can go from the root down to the 2nd in two steps of five semitones, and the 2 times 2 show that you can go from the b7th up to the 3rd in three steps of two semitones. The pentadominant scale is the easiest to play on the M3 so if you are new to improvisation it is a good place to start. Use one of the shapes above to go wild on a blues progression and see what happens.