i have not had the opportunity to attend a DZ wedding (all of my friends are just recently engaged - an exciting time though!), however, one plans to do our chapter dance (a line dance we call the DZ Shuffle to the song Girls Just Wanna Have Fun) and then sing her family song ("Today" - the whole chapter knows all the family songs), which I think will be really sweet
I've been to a couple fraternity weddings, and have seen them lift the bride up on a chair and sing "Dream Girl of PiKA" or other songs such as that.