This took me a minute to realize the automation was available by turning up the BPM slider because there's some time loop it takes to kick in (I'm guessing the instrument plays *after* a time rather than playing right away then waiting a time period) so I was turning the switches back off before the low level sound clicked in.
Other than that, this was super fun! Would love to see this expanded, and have some kind of temporary bonuses or boosts from specifically setting various tracks BPM to set up a "desirable" rhythm (bonus points if we can get another slider for each instrument to control how to offset the instrument, for example: if I set two instruments to 40 BPM, I could have them play alternating rather than always together).
Well done, this is an inspiring combination! It's too bad the web export didn't work :( So far Godot 4 has "just worked" so I'll go knock on wood now.