Craig;
and some of *those* (my own favorite is Squeak) can do music and garbage collection at the same time without missing deadlines.
The thing that matters to me is the immediacy I get from dynamism. I don't ever want to have to stop the processes that make my music. ChucK comes close to that feeling, by making the edit/spork cycle very quick, but to propagate the effects of code changes I still have to kill shreds I would rather leave running during a performance. (Apologies if the situation has changed, I haven't actively used ChucK for my own work in several months. And apologies if I'm rehashing stuff everyone already knows. :)