The Major Scale
The major scale, also known as the Ionian mode, is a prevalent musical scale in Western music, consisting of seven notes with a specific sequence of intervals: whole, whole, half, whole, whole, whole, half. The scale degrees are named: tonic, supertonic, mediant, subdominant, dominant, submediant, leading tone, and tonic (the eighth note being an octave higher than the first).
Structure and Intervals
Major scales are diatonic scales, meaning they follow a specific pattern of whole and half steps. The intervals between the notes create a distinct sound, with the intervals from the tonic to the second, third, sixth, and seventh scale degrees being labeled as "major." The scale can be seen as two identical tetrachords (groups of four notes) separated by a whole tone, each tetrachord consisting of two whole tones followed by a semitone.
Triads and Chords
The triads (three-note chords) built on each scale degree follow a specific pattern. The first, fourth, and fifth triads are major, the second, third, and sixth triads are minor, and the seventh triad is diminished. Similarly, seventh chords built on each scale degree also follow a particular pattern. The first, fourth, and fifth chords are major seventh chords, the second, third, and sixth are minor seventh chords, and the seventh is a half-diminished seventh chord.
Relationship to Major Keys
In music, when a piece is in a major key, the notes in the corresponding major scale are considered diatonic, while those outside the scale are considered chromatic. The key signature of the music will typically reflect the accidentals in the related major scale. For instance, in E♭ major, the notes in the E♭ major scale are diatonic, while the other notes are chromatic.
Other Forms and Notations
The term "major scale" also refers to other scales with a similar structure. The harmonic major scale has a minor sixth and is different from the harmonic minor scale only by raising the third degree. The melodic major scale combines the ascending Ionian and descending Aeolian dominant scales. Abbreviations for major scale keys often use upper-case letters for the tonic, such as 'C' for C major.