The Rochester Red Wings, our AAA Minnesota Twins farm team, will be in town. They're playing Norfolk and Toledo during that weekend. You can buy tickets online, or at the stadium.
Also, Rochester will be having one of its many ethnic festivals, the Greek Fest. This could be a two-fer. It's right by the Eastman House, a museum about photography and the life of Kodak founder George Eastman, so you could hit that and get some baklava at the festival. Eastman is showing an exhibit of travel photography right now.
The weekend of the wedding is also Fairport Canal Days. This is a little further out, but it's a good way to see some great old architecture and celebrate the Erie Canal.
Currently on at the Rochester Museum and Science Center is a planetarium show about shipwrecks in the Great Lakes. And the Memorial Art Gallery is doing an exhibit about Rochester's most famous sculpture, Albert Paley.