thanks for the pointers! I just found a program that does more or less what I want, but I would still like to have a go myself. The link is: http://www.akoff.com/music-composer.html
I gave the program a go, as there is a free trial. I found that it had a hard time doing the conversion (or I am a really bad whistler), maybe there is room for improvements. So, I know it can be done, the question is, does Python have to power to do it? And how did they actually do it anyway... -- http://mail.python.org/mailman/listinfo/python-list