soundtrack
Soundtrack
Write the sound for this film
A film's sound is written for that film: its own instruments, rhythm and harmony in Web Audio, from nothing, in window.SCORE = ac => { … } (oscillators, noise, filters, envelopes, delays: whatever the piece calls for). Drums, a groove or a music-box bed are written the same way, for this film: no two films should sound alike because they share a template. templates/groove.js and templates/score.js are two ready-made scores, used only when the user asks for them; each file documents its options.
render.mjs (from the javascript-animation skill) renders window.SCORE offline with OfflineAudioContext, writes <out>.wav and muxes it into the MP4; the page's live preview plays the same score when clicked.
Don't ask the user to choose a music source up front. At delivery, mention in one line that AI-generated music or their own track also work.