We preview the opening concert of the Racine Choral Arts Society's 38th season .... "Simply Folk" (happening this Saturday night, 7 pm, at First Presbyterian Church) with conductor and founder Jim Schatzman, associate conductor Pat Badger, and three exemplary musicians with local connections who will be part of the concert: Mark Paffrath, Marytha Paffrath, and Zachary Scot Johnson. The concert also includes the world premiere of a piece commissioned from Maggie Burk, director of choral activities at Carthage.