The Major Scale

The major scale is one of the foundations of music theory. Intervals, chords, keys, and modes are defined in relation to it.

The major scale formula

Remember whole steps and half steps from the last unit? A major scale is a sequence of whole steps (W) and half steps (H).

The sequence is as follows:WWHWWWH

Every chord, interval, and key is described relative to the this sequence and the major scale. When someone says something has a "flat 3th" or a "sharp 4th", it's relative to this.