By Denny Dyroff, Entertainment Editor, The Times A good way to spend a day on the penultimate weekend of “traditional summer” (you know, the one that ends on Labor Day Weekend) is to enjoy live music in an open-air setting. A great way to do that is to attend the Third Annual Roots & Blues Fest at Anson B. Nixon Park (405 North Walnut Road Kennett Square, ansonbnixonpark.org) on August 29. Music...