 A Capitol 4th, the annual concert and fireworks display will broadcast live from Washington, D.C. this evening. Smokey Robinson, Fantasia, and Darren Criss are among performers. NPR's Elizabeth Blair has more. In addition to commemorating the nation's independence, two musical anniversaries will be celebrated. Pianist Chloe Flower will perform Gershwin's Rhapsody in Blue, which is marking its centennial.