Scales are collections of notes arranged in patterns of half-steps, whole-steps, or other intervals. Composers and improvisers use scales as pitch resources in their music. They choose specific scales and choose notes from those scales to form melodies and harmonies in their music.

An example of a scale is a Major Scale. A major scale has the following arrangement of half-steps (H) and whole-steps (W):


If we start this pattern on the note D we get a D Major scale: D, E, F-sharp, G, A, B, C-sharp, D.

This is just one of the many possible scales but all scales work in the same way.
List of Scales: