Any stage act or performance will involve an audience. That’s the whole point of the act. Performers know this, and a lot of them react to the audience when they are on stage.
For example, in a dance routine, the dancers cannot move out of their formation to interact with the audience. However, the choreographer usually plans the dance to have certain ‘wow’ points that are most likely to get a reaction from the audience, or at least keep the audience engaged.
Still, wondering how the audience reacts on stage makes a lot of performers nervous. They cannot break the fourth wall to interact with the audience directly. And truth be told, the audience can react in totally unexpected ways – this includes total silence.
That’s where you, the emcee, come in. As the person with the ability to interact with the audience directly, it is your job to manage the audience for the entire event.