Get on Board! carries the subtitle "Underground Railroad & Civil Rights Freedom Songs, Volume 2." I have not heard the first volume, Steal Away, which Appleseed released in 1997. I wish I had. The current recording is not the sort of thing one hears often these days: an exploration of African-American folk music from the decades before the blues came into being, around the turn of the last century (the current scholarly consensus, in any event).

Kim and Reggie Harris, a middle-aged African-American couple from Philadelphia, do a terrific job of reviving both familiar and unfamiliar material. Their singing is straightforward, yet powerful and affecting, and the subtext -- the continuing struggle for human rights and dignity -- is unmistakable, yet too deftly handled to lapse into thudding self-righteousness. The music is set to either unaccompanied or spare, resonant acoustic arrangements.

Joining the Harrises are Honey in the Rock's Bernice Johnson Reagon, the bluesman/songster Guy Davis, former Freedom Singers Matt and Marshall Jones, the actor Danny Glover (reading from Frederick Douglass) and more. Fourteen-year-old rapper Baby Jay Gutierrez even drops in a little hip-hop -- fortunately, just a dollop -- into a medley, called "Row de Boat," of "Joann & Rhody" and "Michael, Row the Boat Ashore."

The Harrises find distinctive ways of delivering revival favorites "Oh Mary, Don't You Weep," "Children, Go Where I Send Thee" and "Down by the Riverside" -- songs it is surely impossible ever to tire of -- but the less-known spirituals, work songs and protest anthems are particular standouts: "Done with Dribber's Dribbin'" (i.e., "Driver's Driving"), the beautiful "Old Tar River" (from the Georgia Sea Islands, with Matt Jones singing lead vocal joined on harmonies by his brother Marshall and the Harrises) and a jazz-inflected reading of the old-time "Trampin'/I Got Shoes." There are also three trad-flavored originals, plus two from the 1960s civil-rights era.

Everybody's in top form, in tune with both the music and the larger vision of hope and justice that the music conveys. These are sounds to please the ear and stir the spirit, and to remind us again of how magnificent songs may rise out of the grimmest circumstances.