The dreaded half diminished chord….who know a flat 5th would cause so many problems….
First and foremost, what is a half diminished chord?
A half diminished chort is a minor 7th chord with a flat 5th instead of natural 5th.
The intervals in a half diminished seventh chord are 1-b3-b5-b7. For example, B-D-F-A = B half diminished chord.
Half diminished chords can be notated as such: bmin7b5, b-b5, or bø.
Let’s look at a few ways how to improvise over half diminished chords.
1. The Locrian mode is commonly used over a half diminished chords. Over a B half diminished chord, use the B Locrian Mode (B C D E F G A B). Below are the diagrams for the different locations to play the B Locrian mode: *Note that you can relate these to C major because B Locrian is the 7th degree of C.
2. Arpeggios! Learning the half diminished arpeggios will help you identify the chord tones. If you are improvising and start to panic about the upcoming half diminished chord, playing the chord tones will save the day! Here are the diagrams for the 5 B half diminished arpeggio shapes:
3. The harmonic minor scale is another common method. Over a B half diminished chord use the A minor harmonic minor scale (A B C D E F G# A).
4. Use the diminished scale. The diminished scale provides more altered tones over a half diminished chord. The diminished scale provides a useful trick when improvising over a minor ii-V-i progression. For Example, if you take a D half diminished - G7b9 - C minor 7 progression, you can use the Ab, B , or D diminished scale over the D half diminished as well as the G7 chord. The diminished scale works because it contains altered tones that work over a half diminished chord, and it is commonly used over altered dominant chords for a b9, #9, and b5 sound.
5. Use a minor pentatonic scale with a flat 5th. When playing over a B diminished use a B minor pentatonic scale with a flat 5th. You can also think of this as a blues scale but without the natural 5th.
