Long before the Avett Brothers began blending the high spirits of rock 'n' roll into the traditional roots of folk and bluegrass, singer and songwriter Sam Bush had successfully extended the accessible cool of mandolins, banjos and fiddles when he established the New Grass Revival in 1972. Bush is set to bring his unique brand of mountain music to Richmond when he co-headlines the National with the Original Wailers Thursday, Oct. 9, at 7 p.m. It remains to be seen whether the Wailers and Bush will play together, but that sure would be interesting. $17-$20. 612-1900 or www.thenationalva.com.