The Wisconsin Singers will pack four decades of hits into just 90 minutes at this Friday?s concert in Overture Hall, entitled “Starstruck” for its tributes to Hollywood celebrities, teen idols and child stars. “It?s a fast-moving show filled with humor and lots of great singers,” said Robin Whitty-Novotny, who has directed the choir for 21 years and is a Wisconsin Singers alumna herself.