As part of a larger scheme for building more coherent melodies, I'm looking into a better grammatical method for representing rhythms.  The additive rhythmic grammar technique may pave the way for better rhythmic coherence in future melodic plugins.

The general idea is to create very simple rhythmic words.  Then, define probabilities for each word - for example, the probability that the word will occur in the first, second, etc. measure.  These probabilities should, for maximum coherence, be either very large (~1) or very small (~0).  Finally, when retrieving the total rhythmic format for a given measure, simply "add" each rhythmic word that has an adequate chance of occuring in the measure.  The key here is that we can treat the words as simple mathematical entities that can be summed, subtracted, and have basic binary operations performed on them.  In this way, it is possible to create a complex rhythmic pattern by using only simple building blocks.

Yes, in reality, it's a very simple idea.  Nonetheless, I've never tried such "additive grammar" before.  Anything is worth trying.