Dixie Chick Goes Solo, Natalie Maines is back in the music business.Ten years after she and her fellow Dixie Chicks were punished by country radio for speaking out against a war and a U.S. president, Maines is preparing to release a solo record. On Wednesday night at Austin City Limits Live, a venue in downtown Austin, Maines performed in its entirety "Mother," the album she will release on May 12. The title track is her cover of the Pink Floyd song from "The Wall" album.....kansascity. She also covers the Jeff Buckley song "Lover You Should Have Come Over," "Without You," a track off a solo album by Eddie Vedder of Pearl Jam, and "I'd Run Away" by the Jayhawks. She brought with her a five-piece band, including lap-steel virtuoso Ben Harper, who produced "Mother" and whose presence was barely acknowledged until late in the set, when Maines introduced him. It was the second performance of her new music (she performed in Lo