Willie Nelson has enjoyed a long career that's made him an icon of country music and a perennial outlaw. After years of hits ("On the Road Again," "Always on My Mind"), celebrated collaborations (with The Highwaymen, Toby Keith, Waylon Jennings) and legal problems (arrested for marijuana possession in 2006; had all his assets seized by the IRS in 1990), Nelson is still touring strong. If you miss this show at The National Tuesday, March 18, at 8 p.m., you might be able to hear what happened. The pioneer sells "Live Willie" wristbands on his Web site that hold entire concerts on a small hard drive. Nelson continues to ride ahead of the pack, on a bus powered by alternative fuels. $55. 612-1900 or visit www.thenationalva.com.