The Stage Manager is Wilder's unique, multi-purpose invention — a part which he himself played on the stage many times. The Stage Manager functions in opposition to the traditional attempt of drama to convince the audience that it is a part of the action onstage. Instead, Wilder has the Stage Manager come to the edge of the stage to remind the audience directly that they are viewers, not participants. At times he helps move scenery and even interacts with members of the audience. But his presence permeates every scene, whether he speaks as himself or through the persona of the druggist or minister.
The Stage Manager's first and most obvious function is to provide exposition of background facts. Traditional exposition occurs when characters reveal facts about place, setting, and plot involvement. Wilder, in defiance of classic method, has the Stage Manager introduce the town and characters. As leader and spokesman, the Stage Manager familiarizes the audience with various aspects of Grover's Corners. Because of his godlike omniscience, he is able to move about freely, ignoring the usual confines of time and space. Perhaps more important, he impels the viewer toward Emily. Also, he assists Emily in returning to life to relive a single day.
From this point on, the Stage Manager's function becomes more complex. He assists the audience in judging the action and evaluating relationships. Without his lecturing and commentary, the viewer, lacking forceful emotion or high drama, is in danger of overlooking the significance among so many minor details. In this way, he becomes an instructor, imparting lessons as a part of Wilder's didactic purpose.
Besides these functions, the Stage Manager serves as an actor. He steps into scenes and interacts with other players. By departing from his job as master of ceremonies and matter-of-factly assuming the role of Mr. Morgan, Mrs. Forrest, or the minister, he retains his humanity. Because Wilder avoids elevating the Stage Manager above the other characters, he makes him a believable outgrowth of town life, on a par with any other citizen of Grover's Corners.
Finally, the Stage Manager speaks the playwright's thoughts and projects his themes directly. When a question arises, the Stage Manager is there to answer it. When Emily has a problem, the Stage Manager is able to solve it for her and for the audience as well. Whatever wisdom Wilder wants to express beyond the dialogue of the play, he puts into the mouth of the Stage Manager. Through this invention of the Stage Manager, the viewer discovers the value of the humblest of everyday transactions. The Stage Manager demonstrates that "an absolute reality can only be inner, very inner " Thus, he functions as the most important actor, as well as a structural element of the play, and also as a facilitator of each theme.