Hello, I have been working with Pico8 and making games for two months.
I'm currently making a rhythm game and implemented rhythm notes, but I found a problem where they were not synchronized with music().
I understood that rhythm notes must be added once every 60 frames to match spd16's music.
Perhaps the music output and frame do not match. Is there a way to do this accurately?

You can use the stat() function to get what note is currently playing.
stat(50) returns 1st voice's note currently playing, 51 52 and 53 for the 3 other channels.
That works well if you are making a sound visualizer, but won't help if you want some visual clue of sounds to come.