## View post (Half dim or dim scale)

LuigiCabrini
Senior Member
Joined: 06/23/00
Posts: 207
05/14/2001 8:52 pm
First of all, get used to calling them minor third intervals, or m3; more people will know what you're talking about.
Anyway, the half diminished scale (though it isn't usually called that) would be the scale associated with the half diminished chord, which is a minor7b5 chord. This is the locrian scale. It is spelt R b3 b5 b7. While it has the two minor third intervals, it also has another major third interval on top of those, making it not fully diminished. The locrian scale is spelled R b2 b3 4 b5 b6 b7.
There are two diminished scales, and while you could think of them as being built on the diminished triad, with those two minor thirds, i think that it's more useful to think of them as coming from the fully diminished 7 chord, spelled R b3 b5 bb7. They are the half-whole and the whole-half scales. Their names explain how they are built, the half whole scale consists of repeating the pattern half step whole step half step, etc. In C it would be C, Db, Eb, Fb, etc. The whole half step is similar, but with a whole step interval first. In C: C, D, Eb, F, etc. They are also called octatonic scales, because there are 8 notes to the octave instead of 7 as there are in regular diatonic scales.
As for use, locrian is used over m7b5 chords (often in the context of a minor ii V I.) The octatonic scales are used over diminished chords, and the half whole is used over many altered dominant chords. Ever see the hendrix chord (E7#9) and not know how to solo over it? Try using the E half whole diminished scale; it will fit and sound interesting.