Which BPM makes a 3 to 10 second Omni clip a whole number of bars?

A 10-second clip is a whole number of 4/4 bars at 60, 72, 80, 96, 120, 144 and 160 BPM, and it is not at 100, 110, 125 or 128 BPM. If you cut a Short from several Gemini Omni Flash 1.1 clips (3 to 10 seconds each on Sume) and put one generated bed under them, choosing a tempo from that list lets every cut land on a bar line.

This post is only the arithmetic and the prompt wording. Music 1.0 and the Music Router have no tempo parameter, so the tempo goes in the prompt as a number, and the Music 1.0 page warns that it is a direction, not a guaranteed value. Check the finished file against your cut list.

The formula

In 4/4 a bar lasts 240 / BPM seconds. A clip of L seconds is a whole number of bars when L divided by that bar length is an integer. The table lists the BPMs that give at least one whole-second clip length between 3 and 10, since those are the lengths the Omni catalog entry accepts.

What this costs on Sume

Omni Flash 1.1 bills per output second, and native audio is always on (the API rejects generate_audio: false). At 720p the rate is $0.125 per second, so a 10-second clip is 10 x $0.125 = $1.25 and a 5-second clip is $0.625. The bed is a flat $0.125 per generation whatever its length. A 5-second and a 10-second clip are therefore the same musical grid at 96 BPM (2 and 4 bars) and differ only in clip price.

For three clips of 10, 10 and 5 seconds at 96 BPM, the grid is 4, 4 and 2 bars: 10 bars in 25 seconds. Footage is 25 x $0.125 = $3.125 at 720p. One bed adds $0.125, for $3.25 before assembly. The prompt line is short: 96 BPM, 4/4, D minor, a break at bar 5.

Prompt and verify

Put the tempo as a number, as the seven-axis table in the docs recommends, and name one moment so the arc has a place to turn, for example breakdown to bass and claps at 0:10. At 96 BPM, 0:10 is the start of bar 5, which is exactly where a second clip begins when the first runs 10 seconds.

Then verify. Play the file and mark where bar 5 begins. If the tempo is off (a track asked for 96 BPM that really runs at 98 BPM reaches bar 5, which is 16 beats in, after 16 x 60 / 98 = 9.8 s, so the downbeat lands 0.2 s early), cut the head of the file with a Timeline audio split at the measured offset, or re-run the generation. A single generation is $0.125, so two attempts cost $0.25, the price of 2 seconds of Omni 720p footage.