Great! Yeah I know Godot! Love it! Thats a lot of samples and a lot of AudioSources haha! One could say you just built your own little MiDi-DAW that's awesome! There are so many possibilities in terms of optimization and how far to go with this :D hit me up if you need help or inspiration, I write my master thesis about adaptive music in video games and this just opened a whole new branch for me xD