Major scale and tones

Sounds: natural, altered, enharmonics

Every scale is composed by natural sounds (c, d, e…) and altered sounds (c#, d#, eb…).

We talk about enharmonic sounds when two names are given to the same sound (c# = db). These altered sounds are 5 sharps and 5 flats:

#	c	d	f	g	a
b	d	e	g	a	b

In harmony we favour using scales with the least number of alterations. The sum of every two enharmonic scales will always include 12 alterations.

Major scales and a table of useful scales

Structure: T stands for Tone and S for Semitone. The roman numerals describe each grade of the scale.

	T		T		S		T		T		T		S
I		II		III		IV		V		VI		VII		VIII

13 scales used in harmony. Of the 17 existing major scales, we use 12 + 1 = 13 of them.
- Only exception: gb and f#, for both of them hold 6 key alterations.

Circle of Fifths

Classification of Semitones

Semitone	Comma	Nomenclature
Diatonic	4	Different name (C - D♭)
Enharmonic	5	Same name (C - C#)

In equal temperament, there is no difference between these two semitones— in fact, the black keys are not double the number necessary. However, in natural temperament and meantone tuning, the difference does exist.

Tonality

Circle of Fifths

The circle of fifths is a particularly useful tool for composition.