unless you have a vocalist at your side, I can't recommend any songs for you. don't play music, play muzak! do a search on the forum; I remember some threads in the past where everyone named a bunch of boring elevator music that makes good background for when music isnt intended to be the focus of people's attention.
There are songs without words.
You & your music will probably be Invisble at this event. It's going to APPEAR classy; that's all.
Is music ever visible?
Only after the composer writes the notes down on paper.