CARTER Jazz violinist Regina Carter poses with her violin at Sweet Rhythm Jazz Club in New York, . For her new album, "Paganini: After a Dream," Carter was granted permission to perform on Paganini's world-famous violin _ so revered it sits under lock and key in Italy, played only by a few privileged artists. The recording, which took place in Genoa, Italy, is the culmination of her odyssey involving Paganini's violin, known in classical music circles as "the cannon" because of its loud, booming sound