With the most genuine of artists you can see the music actually flow the artist(s) in question. This is what makes watching a Live performance really something else (no pun intended) and elevates it to the fantastic art form it can be (music). Then again, deadpan can sometimes do a very similar trick, um maybe. Joanna Newsom, Ian Curtis. Thom Yorke, hell even Michael Jackson, you can see in their performance that Music is what they were meant to do. I'd say creative flow beats a deadpan Johnny Rotten etc.