What the Philadelphia hip-hop ensemble The Roots lacks in mainstream popular recognition they more than make up for in influence. Combining jazz and soul elements, their live shows are frequently touted as among the best in the business. And, oh yeah, they're also the house band for Late Night with Jimmy Fallon. Tonight, Tuesday, Dec. 28. Doors at 7 p.m. Nightclub 9:30, 815 V St. NW. Tickets are $45. Call 202-265-0930 or visit 930.com.