In typically, feature-length scripts have about 15 significant plot beats. Comedies are usually approximately 90 pages long, whereas dramas are usually around 120 pages long. A page is defined as the space between the turning of a page in an electronic document such as a book or screenplay. A beat is the smallest unit of music; it is also called a pulse. In music, each beat has a strong influence on what follows it and can therefore be used to define the beginning and end of phrases, sections, and songs. A single beat can be recognized by its strong impact but also by its short duration (about half a second). Two consecutive beats will often be followed by a pause that could be as long as needed or even longer if someone wants to accentuate a particular moment. A scene contains a series of beats that tell a story through dialogue, actions, and physical settings. Each scene should have a beginning, middle, and end with a clear transition between them. Scenes are important for storytelling because they give shape to the movie and help the audience understand the progression of the plot. A sequence is a group of related scenes that form a logical part of the narrative.