Video · Tested
Add Background Music to a Silent Video With AI, and Check It Before You Post
Most product clips start silent: a phone video of the shop, or a clip from an AI video model with its sound turned off. Music is what makes it feel finished. The trouble with music is that you cannot judge it from a screenshot, and a track can sound fine on laptop speakers and still have problems you only notice on the tenth play.
On September 29, 2026 we asked the Ciyo Agent to put music under a silent 10-second Reel for Bramble & Bloom, a fictional florist, then measured the result with the same tools a video editor uses. The first track had a flaw we would not have caught by ear on one listen.
Start with a silent clip
If you already have a clip, upload it to the board. We made ours in Ciyo: one bouquet photo with GPT Image 2.5 Flare (2 credits) and a 10-second Seedance 2.5 video from it (394 credits), silent on purpose. The agent checked the file and confirmed it was 720 × 1280, 10 seconds and had no audio track.
Silence matters here. Sound that a video model adds on its own (a rustle, a room tone) fights with the music later.
I run Bramble & Bloom, a small flower shop. For this weekend's Instagram Reel, please make one 9:16 photo of our weekend bouquet (peach garden roses, white ranunculus and eucalyptus in brown kraft paper, on a zinc counter in soft daylight, no text), then turn it into a 10-second vertical video with Seedance 2.5: a slow camera arc around the bouquet, petals moving slightly. Make the video silent, with no generated audio. I will add music later.Describe the music like a brief, not a mood
Give the instruments, the tempo, “no vocals”, the exact length and how it should start and end. The Ciyo Agent makes music with MiniMax Music 3 and mixes it into the video in its workspace. It reported 3 credits for the track and nothing for the mix: the track runs the full 10.04 seconds, fades in over 1.2 seconds and out over 1.6 seconds, and averages about −15 LUFS.
LUFS is the unit editors use for perceived loudness. Values around −14 to −16 are common for online video; much quieter and your Reel sounds weak next to others in the feed.
The clip looks lovely. Now add background music to it for the Reel: warm, light acoustic guitar with soft piano, relaxed weekend-morning mood, about 90 BPM, no vocals. It must be exactly as long as the clip (10 s), start softly, and end cleanly with the video rather than being cut off mid-note. Keep the loudness right for Instagram. Save the finished video with music next to the silent one and tell me the credits used.Measure it: the quiet second in the middle
We downloaded the finished Reel and checked it with ffmpeg. The picture was untouched: all 241 frames matched the silent clip. The loudness was −15.2 LUFS with peaks at −1.4 dB, as the agent said, and the ending faded to near silence on the last frame.
But the level curve showed a hole. From about 5.1 to 5.95 seconds the music fell to around −32 dB, roughly 15 dB below the rest of the track. In a 10-second Reel that is a whole second of near silence right in the middle, the moment a viewer decides whether to keep watching.
Ask for a steady track and check again
We sent the measurement back and asked for a new track in the same style with no pause. The agent confirmed the dip (and found a shorter one around 2.5 seconds), made a second track for another 3 credits and reused the same video.
The second version has no break. Its quietest moment between the fades is about −23 dB, a short gap between guitar notes. Its loudness is −14.0 LUFS with peaks at −1.3 dB, and the picture is again frame for frame the silent clip.
| Check | Version 1 | Version 2 |
|---|---|---|
| Length | 10.04 s | 10.04 s |
| Loudness (integrated) | −15.2 LUFS | −14.0 LUFS |
| Peak | −1.4 dB | −1.3 dB |
| Quietest moment between the fades | −32.9 dB at 5.9 s | −23.2 dB at 1.5 s |
| Picture changed | No | No |
| Credits | 3 | 3 |
I measured the track: it drops about 15 dB, to around -32 dB, from 5.1 s to 5.95 s, so the Reel goes almost quiet for a second in the middle. Please make one new track with the same style but a steady, continuous rhythm from start to finish, with no pause or break, keep the soft start and the fade at the end, and save it as a second version. Tell me if the quiet part is gone.When AI music disappoints
Not every test goes well. A vague request gets a generic track, and one listen is not a check. Be specific about instruments and tempo, measure the level curve or at least listen twice on headphones, and regenerate: here a new track cost 3 credits.
Posted 2026-09-29. A video editor gave an AI tool, which he does not name, a raw clip and asked it to colour grade it and add music. He says he got a weak grade and a boring song after 25 minutes, and that he could do the job better in three minutes. It is not a test of Ciyo; we include it as a fair warning that the brief and the checking still matter.
A checklist before you post
Check that the track is exactly as long as the video, that it starts softly and ends on the last frame, that there is no gap in the middle, that loudness is near −14 to −16 LUFS without peaks above −1 dB, and that the picture did not change. Then listen once on a phone with the sound on.
Adding music to a video with AI
Can AI add music to a video I already have?
Yes. In Ciyo, put the clip on the board and ask the Ciyo Agent for music. It generates an instrumental track at the clip's length and mixes it into a new video on the board.
How loud should music for a Reel be?
Around −14 to −16 LUFS integrated, with peaks below −1 dB, is a common target for online video. Our two versions measured −15.2 and −14.0 LUFS.
Why does my AI music have a quiet gap?
A music model can build a break into a short track. Ours dropped to about −32 dB for almost a second. Ask for a steady rhythm with no pause, then measure or listen again.
What did it cost?
3 credits per music track. Making our silent test clip cost 396 credits (2 for the photo, 394 for the Seedance video).
Finish your Reel in Ciyo
Put your clip on the board, describe the music and let the Ciyo Agent mix a version you can measure and post.