if your audience is polite enough they will put up with anything.

That's why its a healthy discipline to work a few tough audiences in ones career. if you've banged your head on a few brick walls you will get to appreciate what a courtesy a good audience is extending to you.

The kind of guy who stands up infront of an audience, unrehearsed, unprepared deserves much worse than he gets from most English folk club audiences. perhaps it would be a good idea to ask whoever is collating this non folkie audience who they are likely to be - age group, ethnic mix, any special interests -obsessions....The name of the game is making contact - give yourself the best chance, the songs of whatever type, can't do all the work for you.