I have those crutches myself I depend on but hey, it's my band. Sometimes, even though I have played a song 100x, when live, I will have a mental block and just can't think of an opening riff or a lead break run. My little onstage "senior moments." Thus every song has a 1 page cheat sheet I refer to in a binder on my stand. I put them in set list order and flip them as I go. 75% of the time I never even look but about 5% of the time it saves my ass. We just added Radar Love to our set list and those bass runs near the end are easy to forget so they are on my cheat sheet :o
Practice and muscle memory help alot. In a blues "jam" I'm not sure if you want music other than chord progressions out front. I have done a few of these and even on my worst playing most of the guys made me still feel welcome. Just relax (easy to say) and play what you feel, if you remeber the correct notes play'em, if not....jam!
Good luck, it takes some guts to get up and jam with a bunch of blues cats ;)
"I once played notes so fast that light emanated from the strings whereupon, I saw God.... who then told me to relax and start playing music."
"I don't want to think about how I am doing it because that just makes it harder." Steve Howe
"You know, once you've had that guitar up so loud on the stage, where you can lean back and volume will stop you from falling backward, that's a hard drug to kick." David Gilmour
Truefire Science Officer (dabgonit....where's my blue shirt!)