I'm a part-time bodybuilder, weighing about 250 pounds. I play with a lot af brand new musicians who are very nervous. I often tell the audience that I am going to deliberatly insert a few "off-notes, go flat occasionally, or sneak in the wrong chord, just to see if they are paying attention." Then, I tell them that, "...if they hear any of them, I'll meet them out back after the show, and we can talk about it!" I've never had any problems. Works every time.