Dear Sean and Rasmus!
Thanks for your answers and for help.
Not long ago I got to know about Theremin Center in Moscow and began to
attend
it. I've heard some of J.C. Risset's compositions there and guessed about
it's possible connections with Csound. 
I'm glad to report the URL of Theremin Center's site (in English):
http://postman.ru/~xmedia/theremin/ . (maybe somebody knows
about it already).