Diminished 7ths, half diminished 7ths

Dim 7th chords:

Dim 7th is not too different in sound than the Dim traid.

You can hear that it doens't change the charcter much.

dim 7 -- 1 b3 b5 7


There are actually only 3 diminished 7th chords.
For this reason, lead sheets do not need to indicate these chords in inversion.

Instead of notating Fdim7/Ab.... it is much simpler to write Abdim7.


Fake books tend to be indifferent about distinguishing between 7ths and plain dim triads since the 2 forms have pretty much the same effect.

You can assume that it is okay to play a dim7th, even if the chart indicates only a dim triad.


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Half - dim 7th chords

The half dim chord often seems to mystify musicians.

Many player who are quite comfy with all the chords we have mentioned so far react with a blank look when asked to play a half dim chord.

Relax.

It is only an inversion of a chord we have already studied: the minor 6th chord.

Cm6 --> If you flip it over to its 3rd inversion --> you have a A half dim chord.

A half dim chord is a slash mark through the circle symbol of dim chord.
Sometimes it is labeled a min7b5.


If you take a min7 chord and flat the 5th -- half diminished.

It is an inverted minor 6th chord.