I have the following problem: whenever I let myself noodle and discover a chord progression I love, that chord progression turns out to be atonal, or practically impossible to fit into a key (e.g. Gmaj-Bbmin-Ebmaj-Dbmaj; or Dmaj#11-C7). And I do love atonal music; by contrast, I am often repelled by patently tonal, diatonic chord progressions. So it seems like the music I compose must be atonal, or at least chock-full of chromaticism. If it's not, I won't like it. But such an approach leaves me paralyzed with an excess of creative freedom. An embarrassment of riches. The next chord can be ANY of the 24 basic triads. No tonality, no limitations. But that means that I can write more than two hundred and fifty-five THOUSAND different four-bar progressions, with a chord change in every bar. How the hell am I supposed to choose which of these 255,000 four-chord progressions I want to have in my song? I don't know how much time it would take me to actually try out all of them; and if I start experimenting with chord extensions and longer progressions, the number of possibilities becomes even bigger. That's why I need a system of composition that will pare the possible chord progressions down to a manageable amount; but that can't be the plain old tonal system, because tonality doesn't really work for me (or I still haven't found a way to make it work).[br]I have quite extensive knowledge of musical modes and experience of modal mixture (e.g. I have composed a piece using eight different modes; I crammed them all into two minutes)... but modality isn't really a system beyond tonality, is it? And in any case, if I can borrow chords from ANY of the 21 parallel modes (which is what modal mixture is about), I'm still spoiled for choice, and therefore confused. How do I choose the Next Chord when I have so many chords to choose from? Is there any atonal (or semi-tonal, or polytonal) system of composition I can use?