Topic 3 A figure, a scale, the regular heptagonal

As highlighted in the photo, the major scale is represented by an irregular heptagon (with seven sides) whose sides follow the same logic of arrangement of tones and semitones as the major scale. If we use the letters instead of the notes, starting from Do and clockwise, we will have: A, B, C, D, E, F, G.

The sides of this heptagon follow this formula:

1) AB = BC = DE = EF = FG

2) EC = GA

As can be seen, sides only have two “sizes”, and we could represent them symbolically with the AB and CE sides. But if in the same way, every major scale follows a precise order of T and sT and this order can be represented with a certain heptagon, we can generalize and say that that particular heptagon represents all the major scales.

If we define AB= 1 m and CE= ½ m (corresponding to 1 T and 1 sT) as the symbolic unit of measurement of the sides of the heptagon, we could generalize and say that:

Irregular heptagon (1 m- 1 m -½ m- 1 m- 1 m- 1 m- ½ m) = major scale (T)-(T)-(sT)-(T)-(T)-(T)-(sT)

Keep in mind that the major scale is the most important scale of all, on which the greatest masterpieces and hits of the past and present have been composed.