Trailer Terminology

Plot Summary
Most trailers have a three-act structure similar to a feature-length film. They start with a beginning (Act 1) that lays out the premise of the story. The middle (Act 2) drives the story further and usually ends with a dramatic climax. Act 3 usually features a strong piece of 'signature music' (either a recognizable song or a powerful, sweeping orchestral piece). The last act often consists of a visual montage of powerful and emotional moments of the film and may also contain a cast run if there are noteworthy stars that could help sell the film.

Voice-over
Voice-over narration is used to briefly set up the premise of the movie and provide explanation when necessary ('In a world...'). Since the trailer is a highly condensed format, voice-over is a useful tool to enhance the audience's understanding of the plot.

Music
Music helps set the tone and the mood of the trailer. Usually the music used in the trailer is not from the film itself (the film score may not have been composed yet). The music used in the trailer may be:

• Music from the score of other films
• Popular or well known music, often chosen for its tone, appropriateness of a lyric or lack-there-of, or recognisability
• 'Library' music previously composed specifically to be used in advertising by an independent composer
• Specially composed music
• Songs, which may include knock-offs of recognizable (but expensive to license) songs

Cast, Crew, and Studio Information
A cast run is a list of the stars that appear in the movie. If the director or producer is well-known or has made other popular movies, they often warrant a mention as well. Most trailers conclude with a 'billing book', which is a list of the principal cast and crew. It is the same list that appears on posters and print publicity materials, and also usually appears on-screen at the beginning (or end) of the movie.

• Studio production logos are usually featured near the beginning of the trailer. Until the late 1970s, they were put only at the end of the trailer. Often there will be logos for both the production company and the distributor of the film.

Technical Elements

• Sound Mix: many movie trailers are presented in Dolby Digital or any other multichannel sound mix. Scenes including sound effects and music that are enhanced by stereophonic sound are therefore the focus point of many modern trailers
• Video Resolution: movie trailers, preceding feature films are generally presented in the same format as the feature, being in the general terms 35mm film or a digital format. High bandwidth internet connections allow for trailers to be distributed at any resolution up to 180p