In music theory, the major scale or Ionian scale is one of the 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, though it may be the hardest to play on the keyboard, is C major, the only major scale not to require sharps or flats, and which uses only the white keys on the piano:

 C major scale (help·info)

In rock and popular music examples of songs in Ionian include REO Speedwagon's "Take It on the Run", The Shirelles' "Will You Love Me Tomorrow", Gordon Lightfoot's "Carefree Highway", and Gin Blossoms' "Follow You Down".

A major scale may be seen as two identical tetrachords separated by a whole tone, or whole step, the new set of steps "Whole:Whole:Half:Whole:Whole:Whole:Half"(in Semi-tone 2 2 1 2 2 2 1). Each tetrachord consists of two whole steps followed by a half step. 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.