I played a wedding a while ago and the suggestion was made not to play "Your Cheatin' Heart", "Please Release Me", and other similar ones. This really suprized me because many years ago in a dance band we played mostly weddings and almost always played these "uppers" as they were quite popular then.
One of my favorites then was "She insulted my apartment, so I knocked her flat".
(Not really, I wonder how many of the younger generation got that one?)
Scott Langholff