Corey Harris has spent his career digging for roots, looking for the links that bind his beloved blues with African music and other tributaries of black music, including old-time jazz and R&B.

On the brilliant 2003 Mississippi to Mali, Harris took his recording equipment to the field in those two seemingly far-apart locales, and discovered they were closer than you might think.

Before that, on 1999's Greens from the Garden, he found common threads between the blues of the Delta and the many variations of Americana that Louisiana has to offer.

For Zion Crossroads, Harris turns his attention to reggae -- real roots reggae, not the often unrecognizable spinoffs that pass for it today.

At times, Zion Crossroads is virtually indistinguishable from the righteous, spiritually motivated, Rasta-centered reggae that first emerged from Jamaica in the early '70s.

Harris' songs here deal with the issues that concerned the pioneers like Bob Marley, Burning Spear, and Black Uhuru, when reggae was vital to the Rastafarian existence, not just another exotic rhythm on the dancefloor.

In "Sweatshop," Harris laments the deplorable conditions under which so many still labor today: "All day on your feet just to make ends meet/So hot it burn your skin, tell you it's a grievous sin." "No Peace for the Wicked," which features Ranking Joe guesting on DJ vocals, is a song of encouragement in light of oppression, and the uptempo "Keep Your Culture" is self-explanatory, asking blacks, simply, "If not you, then who?" Harris uses standard roots reggae instrumentation for most of the album -- guitars, keyboards, horns, drums -- but one of the more interesting diversions takes place on the two-part "Walter Rodney." A tribute to the Guyanese political activist killed by a bomb while running for office in 1980, the song adds the African ngoni, played by Cheick Hamala Diabaté, tying it to Harris' African-themed recordings.

And "Plantation Town" has nothing at all to do with reggae -- it's a nearly traditional country tune, complete with fiddle.

It may not sound like anything else on the record, but its condemnation of slavery is very much in keeping with Harris' wakeup call for unity and harmony in a world that needs it more than ever.