I downloaded this picture and brightened it a little. With a little help from the Viking yearbook I think I've identified everyone but the boy and the girl on the far right: Linda Vaccaro, Donna Tarver, mystery man, Bunnye Buehring, and mystery girl. This must be a prom picture, but that's a guess.
(Update) As you can see by Walt's comment, the girl on the left is Leslie Weber, not Linda Vaccaro. He says it's a photo from a piano recital. Many thanks for the update, Walt.
(Update) Walt's big sister says that's Brenda Weber, not her sister Leslie. (See Cindy's comment below.)