has anyone ever planned or attended a 25th wedding anniversary party??

my parents 25th will be coming up soon. which I plan on throwing a surprise party for them. the only problem is I have no idea what I'm doing. I've never been to a party like that before. all of the sites I read say to hire a dj or live band. the place I'm having it at is a very nice place but not for a band or anything like that.. it's small.

can anyone give me tips or ideas or if you have planned/attended a party help me out with what to do. I don't even know where to start. thanks so much