One thing I knew I wanted before the jam started was adaptive music of some kind. So before I had any gameplay, or really knew what kind of game I wanted to build, I made the music (with two different backing tracks). Then when the spinning theme was announced, I thought it made sense to swap between the two based on whether or not the player was in the act of spinning. From there, once I got to actually adding gameplay, I decided to have every game element happen on a beat of the song rather than on its own timer, and to have all of the sound effects be in the same key as the backing track as well. I'm pretty happy with how tightly coupled the gameplay and the music are.
https://wrywerytwreywery.itch.io/gyre if you want to check it out!