Music legend Willie Nelson will perform Saturday morning at a voting rights rally at the Capitol, lending his name once again to the side opposing Republican efforts to pass legislation affecting the way Texas conducts voting and elections. Nelson's concert will help cap a four-day voting rights march that began Wednesday morning with a Georgetown-to-Round Rock leg, then picked up again Thursday morning with about a 10-mile walk into North Austin that was joined by the Rev. Jesse Jackson, the political activist and former Democratic presidential candidate. Patterned after the Selma-to-Birmingham trek in Alabama that helped define the civil rights movement in 1965, the march will end at the Capitol for a Saturday rally scheduled to begin at 10 a.m.