Three Approaches to Anime Soundtracks: AI Composition, Computer-Generated Scores, and Ready-Made Music Libraries
Sep 27, 2026 · Updated Sep 28, 2026 · 0 views
I had three AIs simultaneously compose music for the same 15-second, silent ice cream animation using three different methods.
Every movement in the animation is synchronized to "120 beats per minute"; licking the ice cream, taking a bite, and the head freezing all occur at fixed intervals. Therefore, as long as the soundtrack is synchronized to this timeline, the animation doesn't need to be redrawn.
A|AI Composition
Google Lyria generates background music, and then adds sound effects from the Pixabay sound effects library.
Results:He got the timing right on his first try—he was off by just 0.019 seconds.
B|Computer-Generated Sheet Music
AI composed an original song: 218 notes, six instruments, all played using computer-generated instrument sounds. All sound effects were also created programmatically.
Results:The notes are written directly on the beat; no other people's voices were used.
C|Ready-made Music Library
Pick a song from the free music library (NCS), then add some free sound effects (Kenney).
Results:It took me four songs to find the right one. The last one was at 126 beats per minute, so I had to slow it down a bit to 120 beats per minute to get it to match.
How was it done? Who did it?
- I said, “Let’s do all three at the same time—I want to see how it works.”
- Have each of the 3 AIs perform a different task; finally, the main AI uses the same ruler to measure all three.
- After listening to it, I made the following requests: “Create two audio tracks for Video B—continuous background music plus sound effects.” “All the sound effects in Video ABC must be different.”
- I told C that the song “didn’t fit at all,” and asked them to pick one with a similar style and tempo and try again.
How Far Has AI Come?
It can be done
- We did all three methods at the same time, and in the end, they all fell into place.
- B I wrote the entire song and all the sound effects myself; I didn't use any sounds from other people.
I still need some help
- AI can't hear—it says so itself. Whether a song works or sounds good is up to me to decide.
- C: Mistakes in the first three songs: The one marked as 120 beats per minute is actually only 95.7 beats per minute; one song has a swing rhythm, and the timing is off throughout another one.
- B The instrument sounds downloaded the first time were actually web files; the first version had only 40 notes and one type of instrument.
- Even the tool used to measure the beat can drift on its own: if the sound shifts by 0.022 seconds, the measured speed jumps from 119.98 to 121.65.
My Perspective
A It's the easiest. B It's the easiest to control—you can change any note you want. C It takes time to pick a song, and the song you choose might not have the exact right beat.
The music and sound effect licenses for each video are listed in the YouTube description | For information on how to create animations, see the article titled “AI Character Animation”
September 27, 2026
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