Word-association test: What comes to mind when you think of banjos? If you said Hee-Haw, Deliverance or The Beverly Hillbillies, you're probably not alone. But music aficionados who believe that banjos and good dental hygiene needn't be mutually exclusive probably think of Bela Fleck. Fleck is to the five-string what Captain Kirk was to the Enterprise -- a pioneer boldly taking his instrument into the unknown. Though Fleck remains a jazz artist at heart, he continues to explore new musical terrain. In April, he issued Music for Two, a disc featuring highlights of a collaboration between Fleck and classical bassist Edgar Meyer. And when he's backed by his longtime band, the Flecktones, as he is on his current outing, Fleck tends to be at his most improvisational and playful.