What? You want a LINK to the answers?! Oh all right. http://en.wikipedia.org/wiki/Classical_music I think comment links don't really link - you'll probably have to copy/paste.
I recognized about 5 of them - 4 in the top row, I had no idea Vivaldi looked like that. The only other one I was a little bit confident about was TchaikovskyJean
Yes, the top row is the easiest, isn't it? Good for you on Tchaikovsky! One of the musicians in our chamber group did not think it could be him because he died when he was 53 and in this portrait he looks so old!