In music theory, the major scale or Ionian scale is one of the diatonic scales. It is made up of seven separate notes, plus an eighth which is the same as the first an octave higher. In solfege these notes correspond to the syllables "Do, Re, Mi, Fa, Sol, La, Ti/Si, Do". The simplest major scale to write or play on the piano is C major, the only major scale not to require sharps or flats, using only the white keys on the piano keyboard: