There are some practical staging considerations that playwrights need to be aware of when constructing a play.
Beginnings and endings, “tops and tails”, the flow of one scene into another is one such consideration. Playwrights need to know how their characters will move from one scene into the next and what demands changes in story location and other story variables impose on actors and stage crew, who must realize these changes physically.
For example, do actors need to change their costumes or age or change their character’s appearance in some way? How long will these changes take? Have you “covered” these changes in your script so that the action continues while the actors are achieving the change? If the location changes, how does the set change and how long will this take? For example, does large furniture need to be struck? How long will this take?
Music/sound is sometimes used to link scenes and to cover for changes. Again, however, length of time is important. Stage time and real time are not the same from an audience’s perspective.
Sometimes the style of the play can aid the writer in this respect. Plays that allow the audience to watch set/costume changes and other mechanisms of performance can increase an audience’s tolerance of the time taken between scenes because the audience becomes involved or interested in the performance process itself. However, the time taken should still be minimized to avoid losing the audience’s “contact” with the story.
Generally speaking, long intervals between scenes break the tension of a play and are therefore not desirable. The task of the the writer is to design the action of the play in a way that will minimize the time taken between scenes to ensure a smooth flow in an acceptable time period.