When you go hear a band, do you want them to sound just like their recordings or do you like them to change things up? What if you are on stage instead of in the audience? Do you try to play your songs the same way every time or do you like to go with the flow? One of the most fascinating aspects of music is the degree to which it is intended or allowed to change from one performance to the next. We can imagine music on a spectrum running from the completely fixed to the com