[PD] pd-based procedural chord progression database..

[Marius Schebella]

Chuckk Hubbard schrieb:
> Two things come to me right away.
> One of the things Bach did was to start using certain notes that
> implied a key change before there was any indication of momentum
> towards a key change.  It's easy to work a Bb into a theme in C
> without giving too much away.  Then when it happens, the change sounds
> like it fulfilled some subtle destiny.  I have *no idea* how you could
> do this with Pd.

if you use Bb in C, it is another chord, C7
(C - C7 - F)

> You can get away with a lot of little borrowed progressions with jazz.
> Any chord whatsoever can be preceded by a dominant 7th, or a tritone
> sub for a dominant 7th, and that in turn can be preceded by a minor
> 7th, or a tritone sub for that, and so on.  You could actually have
> lots of momentary forays that would end up returning to the original
> key.

If you have a 4-bar period, and just just use a II-V-I progression like 
|Dm7 |G7 |Cmaj7|(Cmaj7)| (|Xy| = one bar)
these harmonies can be substituted in many ways, like
|D7|Db7|C6| or |D7 - Ab7|G7 - Db7|C| with two changes per bar.
OTOH the other hand you could use substitutions for major harmonies by 
their parallel minor harmonies |Dm|Em|Am| and of course also the other 
way round |F7|B7|C|. some harmonies are weaker, some are stronger, so 
define, at which time you want to have stronger changes in harmony and 
when there should be little changes. then have other progressions, 
styles, tastes...
m.