If a band is good, they perform songs better or at least as well as the studio recording. As for addressing the audience – do you want the musicians to come out, play, and leave? It's as if they don't see their fans. When I was at a Kipolov concert, the guy interacted very actively with the audience. And yes, Leningrad Rock knows what a backing track is; any band knows that. For the best and most conscientious band, a backing track is a backup option, in case they haven't rehearsed, etc. Even if that's never actually happened in practice.