Major scale
Sequence whole–whole–half–whole–whole–whole–half.
What it means
The major scale consists of seven degrees whose distances obey the sequence whole–whole–half–whole–whole–whole–half. The semitone steps thus lie between the third and fourth and between the seventh and eighth degrees. This distribution is decisive: it produces the major third above the root, which determines the mode, and the leading tone below the root, which carries the cadence.
In the notation
On the natural notes, this sequence results from C without accidentals. Every other major scale needs accidentals so that the pattern is preserved — and from this arises the circle of fifths: each fifth upward adds a sharp, each fifth downward a flat. The key signature at the beginning of the line names the pool of notes, not the key itself; the same key signature applies to a major key and its relative minor.
Musical use
Since the seventeenth century, major, alongside minor, has been the dominant mode of Western music. Its predecessor is the Ionian mode, which was taken into the system of the church modes only late, although practice had long known it.
The strength of the system lies in the cadential gradient: on the fifth degree stands the dominant with the leading tone, on the fourth the subdominant, on the first the tonic. From every degree a triad belonging to the scale can be formed — three major, three minor, and a diminished one, the latter on the seventh degree.
The widespread ascription that major sounds cheerful and minor sad is a simplification: it holds on average, but countless examples contradict it.
The major scale corresponds to the Ionian mode. It can be divided into two identically built tetrachords connected by a whole-tone step: C–D–E–F and G–A–B–C. This property explains the circle of fifths, for the upper tetrachord of one key is the lower of the next.
Performance practice
Practise scales with an eye to the semitone places, not only as finger work — that is where the character lies. Take the leading tone close to the root. And name the degrees while practising instead of merely playing off notes; thinking in degrees is the basis for transposing and analysing.