Just as an addendum to my previous post, if you are not blessed with the ability to memorize lyrics or music, then do what you have to do, and the audience be damned if they don't like.

Whatever gets you through the set(s) and makes it work for you, and makes you feel comfortable on stage. You have to be comfortable and relaxed in order to really be able to ''give'' to and connect with an audience. A little nervousness is okay. Keeps you on your toes!