The diminished scale and how to use this scale building patterns from the diminished scale has always been a bit unclear to me. I decided to delve into this so I could better understand and use these scale and patterns in my music.

I guess the best place to start is to define what a diminished scale is. First lets look at the scale as a shape. This would be the simple part of understanding the diminished scale. It is a symmetrical shape built with alternating half steps and whole steps. This means that there are two shapes to the diminished scale.

1.) whole step/half step
This scale typically used with a diminished chord which has a natural 7.
2.) half step/whole step
This typically used with a dominant 7th chord

The above is a a very simple definition. There are many ways of using this scale.
Because of its symmetrical shape the possibilities of usage can include many types triads and seventh chords and repeating scale fragments to create interesting and tasteful sounds.

Realizing there are two shapes of the diminished chord. The next fact is that there are eight notes in the scale. Consider there are twelve tones in the system most of us are familiar. The 8 note diminished scale is a better fit mathematically with the twelve tones.

There are only three diminished scales. If you were to play a diminished scale from any note and then starting again from the next two half steps when you reach the 4th step, the scale would repeat the same notes that were in the scale played from the first step.

So enough theory for now. Time to get started on the patterns and to explain the theory in action as we go along.