Make a thirty-second cue by counting picture time and musical bars

Lock the timing reference first

Ask for the current picture, its frame rate, its starting timecode, and a statement of what “30 seconds” means in the delivery: exact duration, a pre-roll plus programme, or a cut that fades under a logo. Place markers at the first frame, every editorial beat, the end frame, and any required button or exit. Music can be elastic; picture duration is usually not.

Do not rely on a phone timer after the arrangement is underway. Use the DAW’s timeline and, where relevant, its movie/timecode settings. Logic documents a link between bars-and-beats and absolute SMPTE time; that connection is useful precisely because musical bar numbers and picture positions answer different questions.

Choose tempo from the form

In 4/4, one bar lasts 240 ÷ BPM seconds. To fit 16 bars into 30 seconds, solve BPM = 240 × 16 ÷ 30: 128 BPM. That gives a full 16-bar form with no fractional final bar. To fit 12 bars, the result is 96 BPM. Neither answer is inherently better; choose the one whose energy and edit points suit the picture.

Leave room for the actual events. A brand reveal may need a held chord rather than another drum fill. A line of dialogue may need a thinner arrangement. Place these constraints in the brief before choosing sounds.

Worked example: 30 seconds, 16 bars

A cut begins at 01:00:00:00 and needs music under 30 seconds of product assembly, ending on a logo. At 128 BPM in 4/4, 16 bars equal exactly 30 seconds. Bars 1–4 establish pulse; 5–8 add bass; 9–12 lift with harmony; 13–15 clear space for the logo; bar 16 lands the ending. Place elapsed-time markers 7.5, 15, 22.5 and 30 seconds after picture start. These are seconds, not SMPTE frame fields: convert them using the editor’s actual frame rate and check the nearest frame where a musical boundary falls between frames. If the editor moves the logo, revise the musical plan rather than stretching the final file blindly.

Print useful variants

Deliver a full mix, a no-melody or no-lead option when useful, and a short tail or button alternative only if requested. Each version needs the same picture start, file format, and naming scheme. Watch the video from its actual start after each export; a bounce that starts at bar 1 can still be wrong if bar 1 is not aligned to picture.

Limitations

Tempo arithmetic does not solve taste, copyright clearance, dialogue masking, or an editor’s later recut. A timecode setting alone does not guarantee a client’s playback chain. Use the pre-prompt brief to name the role of the cue, and client-review versioning when picture notes arrive.