Nothing DZ related in my ceremony, but at the reception all of my sisters surrounded me and sang "A Golden Lamp and a Pale Pink Rose." Although, truth be told, I think the girls not from my school were just kind of humming along since not too many other chapters seem to know that song.
Later, we all got in a circle and sang along to "American Pie" which is not, of course, an official DZ song but whenever it would come on in a bar or at a party, was always our signal to drop whatever we were doing, get to the center of the floor and sway goofily.
One thing my bio sister did when she got married this summer was to pin her Kappa key on a blue ribbon to the inside of her gown just under the bodice. Oh, and her sisters serenaded her during the reception but I wasn't familiar with the song so I don't remember what it was