Likewise, an inexpensive controller with a limited range of keys and fewer controls could help you finish the set if your excellent full featured controller stops working during a show. Or you could look for an affordable hardware synth module. If you have a basic synth keyboard that has some sounds in it that you also use as a controller, then you can use the built in sounds if the computer goes down.
Ideally you want to plan and determine what you want to be able to do, then put in the hours configuring and tweaking the settings on the controller and software until you can do those things, and finally practice, practice, practice until you can run through a mock show knowing exactly what your next move is. Setting up mappings, presets, defaults, and saved sessions that are ready to go as quickly as possible is an important part of preparation with a controller. Whatever controller(s) you have you want to learn like the back of your hand and practice with them daily. The core of a successful live show, in my experience, is the same regardless of what equipment is used or what type of show it is: preparation.
