Bass-baritone Gregg Baker will sing about three rivers on the PSO's Thanksgiving weekend program: Mancini's Moon River, Gershwin's Old Man River, and the Volga River. He'll also sing two Lehar songs chosen by Manfred Honeck that were written for tenor voice. Baker talks about his long association with the PSO, his work with Eartha Kitt, his role in an historic Porgy and Bess at Radio City Music Hall, and some pending new roles in his long career.