I do NOT have a "photographic" memory when it comes to learning songs, especially those I have never heard numerous times. SO, when doing the occasional sub gig. I cram and end up writing occasionally lengthy, hopefully concise cheat note/sheets when needed for certain songs, (hoping I can read them without being obvious ) and so as to not train wreck the band. I'd love to hear/see if others do this and what they use, how they lay out their notes for getting thru unfamiliar arrangements. For example: that weird 2nd verse that breaks down and adds a stray bar for a fill, or "hit/accent, or that last chorus that has and extra chord new changes squeezed in. I'd love to see a somewhat well known song, that isn't a straight verse, chorus, double verse, chorus, break, chorus, chorus vamp out and see what you use on a gig for little reminders. Can this be done on a third/quarter or less of a sheet of paper with sucess? If no one else does this you are lucky and I envy you!