I want to draw some paintings of locally famous musicians. I have photographed them during public performances. Do I need to get their written permission to use their image?

If you are just doing the drawings for your personal pleasure and not displaying them publically or selling them, probably not. If exhibiting publically or selling them, probably. I am not a lawyer. See http://www.amazon.com/Business-Legal-Forms-Fine-Artists...d=1211862841&sr=8-2, Tad Crawford's books for legal information for artists. Your local library may have legal guides for artists that you can check out, or go to a bookstore and browse their books to see if you can find the information you need. It is helpful to have books like this on hand, as I reference them quite often.