Close, a File menu item that shouldn't Exit.
Choosing Close, from the File menu, should not make the whole app Exit. I use Close when I've been experimenting and I want to get rid of everything and start again fresh. So instead of just Closing, I suggest a bit more logic. If the Rack has added Instruments or tracks, just close them and revert to default start. But if the Rack is already empty when Close is used, then it would be OK to Exit.