Syncing Music to Picture
When writing music for film, one goal is to sync dramatic events happening on screen with musical events in the score. There are many different methods for syncing music to picture. These include using sequencing software to calculate timings, using mathematic formulas and free timing with reference timings. Composers work using SMPTE timecode for syncing purposes.
When syncing music to picture, generally a leeway of 3–4 frames late or early allows the composer to be extremely accurate. Using a technique called Free Timing, a conductor will use either (a) a stopwatch or studio size stop clock, or (b) watch the film on a screen or video monitor while conducting the musicians to predetermined timings. These are represented visually by vertical lines (streamers) and bursts of light called punches. The music editor puts them on the film at points specified by the composer. In both instances, the timings on the clock or lines scribed on the film have corresponding timings. They are also at specific points (beats) in the composer/conductor score.
Following the action
For the music to follow the movie action, the music must adapt and respond to the actor’s actions. The phenomenon is known as synchronization. If we analyze the medium of film music as a starting point, we can draw analogies between movies and games in their use of music. In film scoring, the composer primarily writes music to enhance the emotional underpinning of a scene. For this to be effective, the composer must write the music in a way that is synchronized to each significant moment of the scene. If the music doesn’t sync, viewers can leave that experience as they begin to notice the music.
In Carl Stalling’s scores of many of the Warner Brothers cartoons, every screen action matches up with a similar motion in the music. For example, if we see a mouse running up a staircase, we might hear the same ascending string run. This technique is frequently referred to as Mickey Mousing. You can hear it in early Disney films and films in the 1930s and 1940s. Dramatic film and game scores often use subtler, less overt techniques to synchronize music events to the player or viewer. For example, they use evolving scores over long periods and transitional materials to get from one cue to another.
Synchronizing the visual performance of a song with the music is more of a challenge than meets the eye. Whenever an actor is seen playing music or singing on camera, it is the music editor’s responsibility to make sure the song is in sync with the picture. Therefore, the editor prepares the music tracks correctly for the re-recording mixer. Today’s high-quality digital cameras can capture “production sound”, that is the sound recorded during shooting.
However, even on a low budget film with a single camera capturing all the sound in this way, the camera’s sync sound recording may not be usable for the final mix. On most films and television shows a separate location sound recordist captures the dialogue on set using a digital audio recorder. If there is any camera music, it will be the music editor’s responsibility to replace the production music track. Also, to prepare, synchronize, fix, and sometimes replace the music, as needed.
A written click track is a method of writing bars of music in consistent time values (i.e. four beats in 02⅔ seconds) to establish a constant tempo in place of a metronome value (e.g. 88 Bpm). A composer would use a written click if they planned to conduct live performers. When using other methods such as a metronome, the conductor has a perfectly spaced click playing in his ear to which he conducts. This can yield stiff and lifeless performances in slower more expressive cues.
When used, click tracks will be designed most often to be continuous throughout a cue. They usually have built-in ritards, accelerandos, and tempo and meter changes. The conductor at his discretion may request to take out the clicks for specific passages. He can also bring them back in at a particular moment in the score.