How the Dixie Chicks Hit the Charts Without Radio Support By JEFF LEEDS In February, eager programmers at the nation's top country music stations got their first chance to hear new music from the Dixie Chicks in four years. But in a suite at the annual Country Radio Seminar in Nashville, brows soon furrowed over what would be the band's first single, the angry "Not Ready to Make Nice,"... "It took our breath away," Julie Stevens, program director of KRTY-FM, a country station in San Jose, Calif., said of the song. Before hearing it, she said, she had figured "fans...