Diminished Harmony is an interesting area of study for the jazz piano student.
Diminished chords are effectively dominant 7b9 chord in disguise. Understanding this relationship will bring a lot of clarity to your understanding of the harmonic purpose of diminished chords
The diminished scale is a very versatile scale that is great for improvisation. There are 2 variations of the diminished scale:
- the half-whole diminished scale (HW Dim Scale)
- the whole-half diminished scale (WH Dim Scale)
The half-whole diminished scale is used for improvisation over altered dominant chords. The whole-half diminished scale is used to play over diminished 7th chords. Effectively they are the same scale, just starting and ending on a different note!
The half whole diminished scale is a great choice of scale to play over minor 251 progressions as it outlines many of the altered tones of minor harmony.
The jazz standard lessons in this course contain examples of diminished harmony so that you understand how to apply these principles in context of actual tunes.