Another thing not mentioned here - this is an arranger forum so many people here use keyboard arrangers, which allow live improvisation. This helps relieve the boredom that comes from playing the same songs the same way night after night. Midi itself allows you to do manyt hings that pre-recorded music does not: midi can control harmonizers, mixers, effects, lights and more. I have a laptop program that can create a live graphics show that is triggered by the midi output of my live performance. Also live midi means the tempo of the song can be changed at any time as well as the mix and even the instruments should you choose. It's a very flexible format.