In my quest for ever more realistic midi modelling, I keep coming up against questions and issues relating to the subtle rhythmic and tempo changes involved in good musical phrasing. After quite a search, I've discovered that such issues are dealt with in a separate theoretical discipline called agogics. (As in agogic accent.)
How can I improve the agogic qualities of my midi output? Besides that, I would like to deepen and broaden my theoretical understanding of rhythm and meter and the nuances thereof in musical performance. The musical style period under consideration is of secondary importance, by the way. I suppose that the basic principles underlying good phrasing are applicable across a wide timespan of musical history.
Edit: rephrased question so as to avoid direct literature requests.