I like gigs where the audience tells us *not* to play Mustang Sally. That's the right kind of audience.
On a handful of weddings we gotten a "don't not play" list prior to the event. Invariably because they've heard those song played by bands that frankly sucked at playing them. And on a few of those gigs, after they've heard us play other stuff, we've gotten asked to play songs that they originally had on the list.
Don't suck and you can get away with practically anything. Last night I played a small club date and we broke into a jam based on an announcement that a red jeep was blocking a delivery vehicle. It was backing the opening act and the band had never worked with that vocalist before and she killed... meaning she entertained the audience.
It was even suggested that she put "Red Jeep" on her next release.