Bursts of drumming from Lee High School’s marching band rattled Water Street in downtown Jacksonville while clusters of bystanders swayed to the beat. Mayor Alvin Brown posed for photos with the J’ville Riders, a red-shirted, black-vested motorcycle group whose rides sat ready. “Bless you. Bless you,” Brown said as he shook hands with a stream of well-wishers. A knot of other politicians joked and pressed the flesh while motorcycle police revved their engines as spectators lined up for the Martin Luther King Jr.