Half Steps and Whole Steps
In Western music, an octave is divided into 12 notes. The distance between each of these notes is called a half step. Two half steps make up a whole step.
When you play a C to a C on the piano using every key (black and white), you are playing a chromatic scale, made entirely up of half steps.
By varying the arrangement of whole steps and half steps, we are able to create different scales. In this post, we'll look at a very popular scale, the major scale.
The Major Scale
The major scale is made up of two tetrachords. (A tetrachord is a set of four notes.) Each tetrachord follows the pattern "whole, whole, half." Next the two tetrachords are joined together by a whole step. So, the complete interval pattern of a major scale is "whole, whole, half, whole, whole, whole, half."
|Major scale, on the staff.|
This interval pattern (W, W, H, W, W, W, H) is true for all major scales. Note that, in major scales, the half steps occur between scale degree 3-4 and 7-8.
Tip: In the key of C, the major scale turns out to simply be every white key on the piano (C to C).