PBS
Pbs: American Roots Music
If teaching a unit about the history of popular music in America, this PBS web site supporting their four-part TV broadcast of a few years ago would make a great resource. Includes lesson plans and oral histories too.
Black Past
Black Past: Fisk Jubilee Singers
In this interesting encyclopedia article, you can read about the beginning of the Fisk Jubilee Singers, a gospel group which performed spirituals all over the country and the world.
Howard University
Howard University: The Fisk Jubilee Singers
Some great photos and a look at The Fisk Jubilee Singers' 1885 travel logbook from their European trip.