If you liven up the atmosphere before singing on the stage.

Nothing can be said. Mainly say something that can make the audience concentrate on listening to you. The acoustics are good. Don't be crazy. At first glance, you don't seem to be singing seriously. At least I think so. Don't eat greasy food and fish before singing. Of course, if you let rock and roll or something, that's another matter. Not only to concentrate, but also to talk crazy. For example, this is a joke, and it can drag on two sentences of English if it is high! If you sing this song directly, there is no prelude, it is a song that shows your personal singing skills. Before you sing, make the audience completely quiet and pay attention to your voice! I especially like lyric, oratorio or light accompaniment music. It feels very comfortable!