Music to Picture (.... and a cool free Cue Calculator)

Synchronisation of Music to Picture

When writing music for a motion picture, the composer has to decide where music will best serve the drama; for example where the music will serve to heighten an emotion already in a scene or perhaps reveal some aspect of the drama that the director cannot communicate by pictures alone. As an example of this, imagine a scene of a man getting out of a car and walking towards a house. If this were accompanied by breezy, light music, the audience's reaction would be very different from if the same scene was accompanied by dark, sinister, mysterious music. Two important terms in film and television music derive from the distinction between "source music"; music which appears to come from a source in the picture (a radio turned on, an orchestra or a song and dance number) and music which recorded after the dialogue has been recorded on location or on the "sound-stage" where the film set is constructed. This second type of music is known as underscore and, although composers sometimes do compose source music, the more normal role for the film composer is the invention of the underscore.

Spotting, Cues and Hits

The composer and the director (and others including the music editor on a large production) decide each piece of music, its duration and exact timing in a process called the Spotting Session; each musical piece being referred to as a "cue". This is equally true for source music and underscore. In addition to the timing of each cue in relation to the film as a whole, the director and composer have to decide where a particular musical event is required to coincide exactly with an on screen visual event, this being known as a "hit". The judgement as to where a musical event "hits" a visual event on the screen is one of the great skills of the film and television composer. To some extent this is dictated by the genre of film; comedy often "hitting" visual events more often than serious drama. Indeed for serious drama, more than one author has referred to the "counterpoint" that needs to exist between the music and the on-screen visuals. Cartoons are the great example of the use of musical hits, where each stealthy footfall is accompanied by pizzicato celli and each eye blink by two-note, falling xylophone phrase! The great Carl Stalling of Warner Brothers is largely responsible for inventing these marvellous musical ideas. That Stalling's style would be inappropriate in an action picture or a thriller is obvious; indeed the tendency to over-hit visual action in a musical cue is disparagingly referred to as "cartooning" or "Mickey Mousing"!

Almost universally, the film composer will work to a NTSC copy of the "fine-cut" or "locked-picture" of the film with burned in timecode (like the one shown above). The fine-cut is the edited version of the film, derived in turn from the working "rough-cut". (Composers rarely begin writing music until the locked-picture has been edited and approved by the director.) This NTSC copy of the fine-cut will be generated from a telecine dub of the 24 frames a second (FPS) film. (For a television composer working in the PAL world, the composer will obviously work from PAL videotape.) If the score is purely electronic and sequenced, the composer will often require nothing more than this VHS copy of the locked-picture. Typically this copy, along with the visual timecode burned into the image, will also have one of the stereo audio tracks devoted to longitudinal time code (LTC): the other track being reserved for a rough-mix of the dialogue track recorded on the sound-stage. The composer has thereby nothing more to do than to synchronise a MIDI sequencer to longitudinal timecode coming from the video tape. Most modern sequencers provide for this type of synchronisation via MIDI Timecode. With the advent of excellent scoring packages and the requirement for better Mock-ups (synthetic versions of eventual orchestral cues for early approval by the director), even orchestral composers now tend to use sequencers slaved to timecode.


Film editors still break down a full-scale feature film into smaller "reels" of about 20 minutes duration. For that reason individual music cues are still annotated in relation to these reel numbers so that the first music cue on reel one is referred to as 1M1, the second cue being referred to as 1M2. On the second reel, the music cues are referred to as 2M1 and 2M2 and so on. By the time the Master Cue Sheet is assembled, the composer will have given each cue a verbal title but on the spotting notes, each cue is simply referred to by this reel and cue number. A short section of a typical Spotting Sheet for feature film is illustrated below.

Clicks, Streamers and Punches

When a film or television score calls for real musicians, this demands other forms synchronisation as the musicians play along to a projected version of the film usually under the auspices of a conductor. Two methods are typically used, the "click-track" and "streamers and punches". A click-track was originally derived by punching holes in the side of the film where the optical sound track appears. As white light reached the photo-cell, a loud click was produced when the signal was reproduced by headphones or a loudspeaker. If a hole was punched every 24 frames, the click appeared once every second. In musical terms this would be referred to as 60 beats per minute (BPM). Every two frames and the click track would be at 30 BPM and so on. Smaller divisions of tempo were derived from sub divisions of frame length. The are four sprocket holes adjacent to each frame of 35mm film like this........

There are therefore eight, well-defined positions in each film frame where the click-track "punch" can be made; against each sprocket hole and between each sprocket hole in each frame. These positions being referred to as zero through seven. For a tempo slightly lower than 60 BPM, the film was punched at 24 frames plus one eighth of a frame: this click track tempo being referred to as 24-1. Whole books were (and still are) published with tables relating musical tempo to duration and click track markings. Some composers "swear by" these publications and find them invaluable, but they are derived from just a couple of linear mathematical expressions.

Although the modern, electronic metronome, synchronised to timecode, has now replaced the laborious process of punching holes in literally thousands of feet of film, you will often still see musical tempo referred to in Hollywood in the form of frame numbers, sprocket holes and spacers rather than the more common BPM.

For the purposes of calculation and translation between elapsed time, BPM and frame-numbers, the first step is to remember that the term 12-1, 12-2, 12-3 and so on, really mean 12 and one-eighths, two-eighths, three-eighths. These fractional expressions make life much easier when calculating. So, if N is the number of frames, we can say,

	N - 0	= 	N.0
	N - 1	= 	N.125
	N - 2	= 	N.25
	N - 3	= 	N.375
	N - 4	= 	N.5
	N - 5	= 	N.625
	N - 6	= 	N.75
	N - 7	= 	N.875

To translate to Seconds per Click (S),

	S = N/24

And for BPM,

	60/S = BPM
The click-track is played to all the musicians in the film orchestra as well as the conductor via headphones and each uses this as the main guide to musical tempo. The click track is a very powerful technique but its inevitable mechanical genesis tends to result in a rather mechanical performance. Where the composer and/or conductor wish to keep the synchronisation between picture and music somewhat more fluid on artistic grounds, a simple stopwatch approach can be used, except that this technique makes synchronising to hits very difficult.

A combination of benefits results from the technique known as streamers and punches (sometimes referred to a "picture cueing"). This technique ensures synchronisation on the hit but otherwise leaves the conductor a degree of freedom in terms of tempo and pacing. Each streamer and punch is derived, once again, by punching a hole in a film frame; but this time, instead on in the soundtrack portion of the frame, in the visible portion. And a much larger punch too! In fact, on the exact frame where a hit is required the film is punched so that a good deal of the entire visible proportion is removed. The preceding 48 frames are then scored so that the emulsion is removed in a long diagonal line. When projected, this technique results in a bright, near vertical line moving from left to right across the frame and finishing with a bright, white flash as shown here.......

Using this technique, the conductor can conduct relatively freely and has, by means of the streamer, a two-second warning of a hit, the exact position of the latter indicated by the bright flash of the punch.

Cue Calculator

Whichever system a composer uses, once the various "hits" have been decided, she must first decide the best musical tempo for the cue, to ensure that the hits coincide with musical beats. Various books, tables and music software exist for this task. However, I use an Excel spreadsheet that I developed myself. You can download it HERE.

You'll see that the spreadsheet has various fields marked in YELLOW. These are free fields and you can change the data in these fields. The spreadsheet calculates timecode on the basis of tempo, frame-rate and time-signature. You can also program the timecode offset of the first cue point. Have fun!


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© Richard Brice 2002. All rights reserved. Newnes, CYP other information by permission