Dixie Chicks lead singer Natalie Maines has been busier as a parent and an activist than as a musician since 2007, when the chart-topping country trio went largely dormant. But Maines is back this spring with a new album, Mother, that's due out in May. The album, a rock record, pairs a handful of originals with covers of tunes by Jeff Buckley, Ben Harper and Pink Floyd, whose song "Mother" doubles as the title track.