Just had a look at your website and the band looks good. Dont change too much, you don't need to go cheesy like some of the suggestions above. They've booked you because they want some better music than "Once, Twice, Three Times a Lady". Groan. I'd maybe just learn 4 or 5 older songs that will appeal to the parents and slot them into the set. Suggest: Town Called Malice, 20th Century Boy, something 60s (My Generation, Beatles etc) something 80s, and I hate to say it, Brown Eyed Girl. People love that song when they're p1ss3d. Good luck, hope it goes well.