repurposing pentatonics pars iii

One interesting thing to do with pentatonic scales is to use them as a way of creating totally chromatic music -- i.e. music constantly using all 12 equal tempered pitch classes.

Obviously a pentatonic scale has 5 different tones. If you subtract that from the total available 12 you're left with 7 pitches. The interesting thing here is that most scales have 7 tones. Consequently if one person/group of performers utilizes a pentatonic scale and another person/group makes use of some 7 note scale the result will be that all 12 tones are being used.

So what 7-toned scale is left over? Let's use a C minor pentatonic scale and see:

C minor Pentatonic: c, eb, f, g, bb
Remaining notes: c#, d, e, f#, g#, a, b

Rearranging these 7 remaining tones we get:

a, b, c#, d, e, f#, g#

...that's right, an A major scale! And for me it's easier to think of this as a B dorian:

b, c#, d, e, f#, g#, a

and that's because then we get this easy-to-remember relationship:

Any minor pentatonic scale played along with a dorian mode 1/2 step below the minor pentatonic will yield the total chromatic.

But there are other ways of conceptualizing the relationship between these 2 scales. E.g. C minor pentatonic is also Eb major pentatonic, which means that there's a tritone relationship between the 2 scales (Eb and A major). And actually this one is pretty nice because the tritone is symmetric, so you could flip the scale types while keeping the roots and you'll still end up with all 12 tones (A minor pentatonic and Eb major).

This way of conceiving of totally chromatic music has a nice benefit of building in some easy to understand structure...give it a go and see what happens.

See also: repurposing pentatonics part i, part ii.