True, but that has been covered ad nauseam on other threads, with people pointing out that it is generally bad form - apart from lack of emotion, you cannot connect with your audience if you are staring at something else, if you cannot memorise sometimes only a couple of verses or a basic chord sequence perhaps you shouldn’t be performing in public yet, plus it’s arguably disrespectful to your audience “here’s a song I’d like to sing but I can’t be bothered to learn the words”.