Beat-sync montages: align the songs own structure, dont splice

For music-driven video edits in ffmpeg: beat-track the song (librosa), then set the music start offset so the tracks OWN breakdown/drop land on your footage moments (offset = song_drop_time - timeline_drop_time). One continuous audio stream with a volume expression (if(lt(t,A),bed,if(lt(t,B),duck,full))) beats splicing two sections. Also: detect the real event onset in diegetic audio via RMS at ~20ms hops instead of eyeballing - announcement cheers peak later than they start. Cheap creative wins from a photo library: play burst near-duplicates at 7-8 fps as stop-motion, and build grid walls with overlay enable=gte(t,k*beat).