I keep thinking that I eventually want to play around with actually constructing animation so I made a short test youtube thing to see if I could get just a series of pngs to line up correctly with music, using ffmpeg.
Short answer: no, I can't? Or at least I did something wrong. Not sure what. Or at least the video transitions always come a little bit before where I thought the beat was supposed to go. Maybe I should try something with less muddy audio.