In releasing "57th and 9th," all those public relations people and music reporters kept talking to Sting about how this was his first rock album in years. But to Sting, the former frontman of influential British export The Police, it didn't exactly feel that way. "I play rock and roll every night, and it's been part of my DNA since I was 7 years old," he laughed in an interview just weeks ago. "That puzzles me a little bit."