The most common scale in Western music is called the major scale. This scale is based upon a sequence of both tones and semitones, and is sometimes referred to as a diatonic scale. Here is the major scale sequence;
Starting on the C note and following through this sequence gives the C major scale;
and in musical notation.
Roman numerals are used to number each note of the major scale. Thus F is the fourth note of the C major scale, G is the fifth, and so on.
The major scale will always give the familiar sound of DO, RE, MI, FA, SO, LA, TI, DO.
The major scale always uses the same sequence of tones and semitones, no matter what note is used as the tonic. The following table list the 13 most commonly used major scales.
You will notice that, in order to maintain the correct sequence of tones and semitones, all major scales except C major involve the use of either sharps or flats. You will notice, when playing these scales, that they all maintain the familiar sound of DO, RE, MI, FA SO, LA, TI, DO.