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In music theory, the major scale or Ionian scale is one of the most commonly used diatonic scales. It is made up of seven distinct notes, plus an eighth which duplicates the first an octave higher. In solfège these notes correspond to the syllables "Do, Re, Mi, Fa, Sol, La, Ti/Si, (Do)", the "Do" in the parenthesis at the end being the octave of the tonic starting pitch. The simplest major scale to write is C major, as it is the only major scale not to require sharps or flats:
The sequence of intervals between the notes of a major scale is:
- whole, whole, half, whole, whole, whole, half
In semitones, this is
- two, two, one, two, two, two, one (2 2 1 2 2 2 1)
Therefore, a major scale may be seen as two identical tetrachords separated by a whole step. Each tetrachord consists of two whole steps followed by a half step: whole, whole, half. Western scales do not skip any line or space on the staff, and they do not repeat any note with a different accidental. This has the effect of forcing the key signature to feature just sharps or just flats.
Scale degrees 
The circle of fifths 
The circle of fifths, first described in 1728 by Johann David Heinichen in his book Der General-bass, has been used ever since as a means of illustrating the relative harmonic distance between musical keys.
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. 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).
See also 
Further reading 
- Bower, Michael. 2007. "All about Key Signatures". Modesto, CA: Capistrano School (K–12) website. (Accessed 17 March 2010)
- Jones, George Thaddeus. 1974. Music Theory: The Fundamental Concepts of Tonal Music Including Notation, Terminology, and Harmony. Barnes & Noble Outline Series 137. New York, Hagerstown, San Francisco, London: Barnes & Noble. ISBN 978006401374.
- Kennedy, Michael. 1994. "Key-Signature". Oxford Dictionary of Music, second edition, associate editor, Joyce Bourne. Oxford and New York: Oxford University Press. ISBN 0-19-869162-9.
- Yamaguchi, Masaya. 2006. The Complete Thesaurus of Musical Scales, revised edition. New York: Masaya Music Services. ISBN 0-9676353-0-6.
- Listen to and download harmonised Major scale piano MP3s
- The major scale for guitar in one position, with derivation