One 1898 cakewalk is called “Who Dat Say Chicken in Dis Crowd.” The music for a 1918 number, “Somebody’s Done Me Wrong,” is illustrated with a black pastor who has a gun concealed in his pulpit and is glaring balefully at his congregation. John T. Reddick, a Harlem historian who is African-American, has spent three years assembling the memorabilia on view. He has also pieced together how the neighborhood’s black composers, performers and music publishers collaborated with Jewish counterparts to sell ragtime, jazz, blues and patriotic marches.
