Documenting your concert can be more involved than just getting a set list. My notebooks contain all kinds of details and memories, some having nothing to do with the actual set list, that provide a lot of color for my write ups.
Often, bands don't announce song titles. When you have to grab lyrics from unfamiliar songs, a notebook comes in very handy.
Jaco died for our sins so that modern bass players could be free to play more and be heard.