Symmetric scales

The scales described in this section are the building blocks of the system I am proposing for the M3. I cannot emphasize enough how important it is that you understand the symmetry of the three main scales (pentatonic, hexatonic, and pentadominant) before you start looking at their shapes on the fretboard.

Pentatonic, Hexatonic, and Pentadominant

Recall that the three most important chord types are major, minor, and dominant. It is natural to assume that there is one scale for each chord type but in fact it is more practical to consider major and minor to be 'similar' and to consider dominant to be the odd one out (this argument is made even stronger when we include altered chords, which are effectively variations on dominant). As mentioned in the section on clock-centric scales, pentatonic fits both minor, major, and dominant; hexatonic fits major and minor; pentadominant is for dominant only. I cannot resist getting carried away with some childish names here, so I will venture that on the clock the pentatonic looks a bit like an ice cream, the hexatonic like the Batman logo, and the pentadominant like a parachute. Even if you find my choices of visual symbols silly I hope you agree that they clearly demonstrate the left-right symmetry of three scales. Notice that the three visual symbols -- the ice cream, the Batman logo, and the parachute -- carve out a piece of the clock for intervals of one or three semitones but not for two semitones.

Chords/Scales Pentatonic Hexatonic Pentadominant
Major Yes Yes No
Minor Yes Yes No
Dominant Yes No Yes

It is time to study the individual notes in the three scales.

Have a good look at the diagram on the right. The note numbers inside the circles are for minor, the numbers outside the circles are for major or dominant. Even though the left-right symmetry of the pentatonic and hexatonic scales appear strikingly different, they are actually very similar since the hexatonic is constructed by adding a single note to the pentatonic (in major the 7th or, equivalently, in minor the 2nd, usually called the 9th). In each of the three scales the most common interval between adjacent notes is two semitones. Consequently, you can memorise the scales efficiently by knowing the intervals of 1 and 3 semitones only. There are only two of those in each scale and they are clearly pointed out by my silly visual symbols. An interval of two semitones is trivially easy to see and play on the M3 so you will not have any trouble connecting the notes through those segments. Only intervals of 1 and 3 semitones need special attention.