The major scale (or Ionian mode) is one of the most commonly used musical scales, especially in Western music. It is one of the diatonic scales. Like many musical scales, it is made up of seven notes: the eighth duplicates the first at double its frequency so that it is called a higher octave of the same note (from Latin "octavus", the eighth).
The simplest major scale to write is C major, the only major scale not requiring sharps or flats:
The intervals from the tonic (keynote) in an upward direction to the second, to the third, to the sixth, and to the seventh scale degrees of a major scale are called major.[1]
A major scale is a diatonic scale. The sequence of intervals between the notes of a major scale is:
whole, whole, half, whole, whole, whole, half
where "whole" stands for a whole tone (a red u-shaped curve in the figure), and "half" stands for a semitone (a red angled line in the figure).[2]
Whole steps and half steps are explained mathematically in a related article, Twelfth root of two. Notably, an equal-temperedoctave has twelve half steps (semitones) spaced equally in terms of the sound frequency ratio. The sound frequency doubles for corresponding notes from one octave to the next. The ratio is 3/2 = 1.5 for a perfect fifth, for example from C to G on a major scale, and 5/4 = 1.25 for a major third, for example from C to E.
A major scale may be seen as two identical tetrachords separated by a whole tone. Each tetrachord consists of two whole tones followed by a semitone (i.e. whole, whole, half).
If a piece of music (or part of a piece of music) is in a major key, then the notes in the corresponding major scale are considered diatonic notes, while the notes outside the major scale are considered chromatic notes. Moreover, the key signature of the piece of music (or section) will generally reflect the accidentals in the corresponding major scale.
For instance, if a piece of music is in E♭ major, then the seven pitches in the E♭ major scale (E♭, F, G, A♭, B♭, C and D) are considered diatonic pitches, and the other five pitches (E♮, F♯/G♭, A♮, B♮, and C♯/D♭) are considered chromatic pitches. In this case, the key signature will have three flats (B♭, E♭, and A♭).
The figure below shows all 12 relative major and minor keys, with major keys on the outside and minor keys on the inside arranged around the circle of fifths.
The table indicates the number of sharps or flats in each scale. Minor scales are written in lower case.
The numbers inside the circle show the number of sharps or flats in the key signature, with the sharp keys going clockwise, and the flat keys counterclockwise from C major (which has no sharps or flats.) The circular arrangement depends on enharmonic relationships in the circle, usually reckoned at six sharps or flats for the major keys of F♯ = G♭ and D♯ = E♭ for minor keys.[3] Seven sharps or flats make major keys (C♯ major or C♭ major) that may be more conveniently spelled with five flats or sharps (as D♭ major or B major).
Broader sense
The term "major scale" is also used in the names of some other scales whose first, third, and fifth degrees form a major triad.
The melodic major scale is the combined scale that goes as Ionian ascending and as Aeolian dominant descending. It differs from melodic minor scale only by raising the third degree to a major third.[6]
^Drabkin, William (2001). "Circle of Fifths". In Sadie, Stanley; Tyrrell, John (eds.). The New Grove Dictionary of Music and Musicians (2nd ed.). London: Macmillan Publishers.
^Rimsky-Korsakov, Nikolai (2005). Practical Manual of Harmony. Carl Fischer, LLC. ISBN978-0-8258-5699-0.
^Tymoczko, Dmitri (2011). "Chapter 4". A Geometry of Music. New York: Oxford.
^Stetina, Troy (1999). The Ultimate Scale Book. p. 59. ISBN0-7935-9788-9.
Further reading
Bower, Michael (2007). "All about Key Signatures". Modesto, CA: Capistrano School (K–12) website. Archived from the original on 11 March 2010. Retrieved 17 March 2010.
Kennedy, Michael (1994). "Key-Signature". In Bourne, Joyce (ed.). Oxford Dictionary of Music (2nd ed.). Oxford: Oxford University Press. ISBN0-19-869162-9.
Yamaguchi, Masaya (2006). The Complete Thesaurus of Musical Scales (Revised ed.). New York: Masaya Music Services. ISBN0-9676353-0-6.