In Jules Allen’s Marching Bands, a stunning collection of social documentary, portraiture, and panoramic photography, he takes us into this behind-the-scenes world of African-American marching bands all over the country. The roots of historically black college marching band performance stretch back to the post-Civil War period, when newly freed African Americans began to experiment with sounds, styles, and what it meant to be an American citizen. By Salamishah Tillet.