Contemporary synchronization techniques
Once a film has been completed by the director, the composer will view the film at least twice - once in an "initial screening", then in more detail, scene by scene when the composer will decide where the music for each scene will begin and end. This is known as "spotting" the film and this meeting will include the film's producer, director, composer and music editor. From "spotting notes" the music director will write "timing breakdown notes" for the composer. This breakdown is a detailed description of each scene that requires music
As soon as the breakdown has been compiled, the composer will "lay out" the score onto manuscript paper, mapping out meters and barlines in a beat by beat layout of the music that is to be composed. Tempos and number of beats need to be calculated if the music is to stay in exact synchronization with the images. These calculations are determined by use of a "click track", which is a series of steady ticks that can be adjusted from 40 to 208 beats per minute. The click track is therefore a form of metronome that allows the composer to decide how fast or how slow the music for a particular scene should be. Prendergast defines the click track as "a synchronous metronome that is locked to the picture, thus enabling the music to stay in synch with the picture" (p.263).
Music is recorded on tape known as "magnetic track" and is coated in an oxide surface (like normal audio or video cassettes), though it looks like normal 35mm film. Magnetic track has the same number of sprocket holes as normal film (four per frame) and is passed over the sound head at the same rate as the film is passed through the projector. Click tracks are usually recorded onto opaque leader tape, and holes are punched into it - holes that would produce a popping sound when passed over the head of an audio film machine.
To determine the click equivalent of any tempo, the composer will start a stopwatch at the beginning of his piece of music. He/she will stop the watch on the 25th beat of the music when the reading will be the same, numerically, as the equivalent click. The difference is that the click tracks are read in eighths. so a stopwatch reading of 10.5 seconds will have a click equivalent of 10 4'8. 14.5 seconds will be read as 14 2/8 etc.
Click track numbers give information as to the number of frames per click, which is inversely proportional to the standard metronome markings (which gives beats per minute). Since there are 1440 frames per minute (42 X 60), the metronome markings can be discovered by dividing the number of frames per minute by the number of frames per click.
e.g. 12 clicks per frame = 1440/12 = 120bpm.
10 4/8 clicks per frame = 1400/10.5 = 137.14bpm
The main advantage of a click track is that it cuts down the time taken to compose a soundtrack and helps the conductor of the orchestra pinpoint specific cues during the recording stage. The disadvantage of using a click track is that it allows little flexibility for the composer when the tempo is locked to a specific click. By using a variable click track it is possible to include musical devices such as accelerandos and ritardandos which may help make the music more expressive. This will entail more calculations on the composer's (or music editor's) part but computer programs have been developed to do this. To be sure of total accuracy and precision with the use of clicks, there exist "click books" which contain tables of timings in both clicks and beats per minute. The first click book was assembled by the music editor Carroll Knudson in 1965, and the click book is often known as the Knudson book.
Click tracks aren't always used in film composition. A technique known as "free timing" makes use of "streamers" or "punches" for synchronization. Streamers are created by scratching the emulsion off a film in a diagonal line. This line usually lasts around two seconds and covers three feet of film. Slower tempos may require longer cues of up to three or four seconds. When the film is projected, the streamer will appear as a vertical line moving across the screen from left to right, and the composer's cue point will come when the streamer reaches the right hand side of the screen. Streamers are usually notated above the score as a circle. Another conducting aid used to aid synchronization are ''punches", notated in the score as + or – superimposed over a circle, and are multiple holes punched in the film with a standard paper punch (or added electronically to videotape) that produce a series of flashing light pulses on the screen. Again these are cue points for the composer and for the conductor during the recording stage, and can be seen without looking at the screen. The main advantage of using a streamer is that it allows the conductor a few seconds to anticipate beats. Streamers and punches are often used to help the conductor synch the music without the use of clicks, and are at their most useful when used in combination with clicks. e.g. in rubato or a tempo sections.
A different kind of synchronization will be required for a practise that is known as "tracking" - i.e. adding an existing piece of music to a film as a "temporary soundtrack" until the original score is ready. The main reason why filmmakers use these temp tracks include
i ) to improve screenings to producers. Studios, network executives and preview audiences during various stages of postproduction. This helps the filmmaker avoid screening the film without a score. which tends to make a film less attractive to prospective buyers.
ii) to help find a "concept" for the score. The composer, director or music editor will often find inspiration for the score by using existing pieces of music inserted into different scenes.
Using temp tracks brings about its own synchronization problems in that the music is not composed with the visuals in mind, so the pre-existing music has to be edited to suitably fit the scene in which it is being used. This is a tedious job and is often left to the music editor.
One of the final stages of recording and synchronization is the dubbing process, which blends together dialogue, sound effects and music. The process begins with predubbing, which will often involve the composer, and is the stage where the sound engineers will become aquainted with the music. The actual dubbing stage can often take two weeks or more for a big-budget movie, while the predubbing will take anything between a few days to a few weeks. The process usually takes place on a dubbing stage specially built for the purpose of dubbing, and will usually involve at least three individuals, who serve as "mixers", sitting at a mixing desk in front of a large motion picture screen. Each mixer handles a different aspect of the sound and they will be known as the effects mixer, and the music mixer, both of whom will be taking orders from the dialogue mixer.