SATURDAY'S big demonstration on the Mall against apartheid, nuclear arms, underemployment and intervention in Central America will no doubt recall the civil rights and anti-war demonstrations of the '60s. Not only will the marchers look familiar, but many of the entertainers will be the same singers who've been performing at such marches for 25 years. Among the scheduled performers are Pete Seeger, Luci Murphy, Lifeline, Ruth Pelham and Dave Littman.

The march is also a reminder that political folk music hasn't disappeared; it has merely been pushed off the major record labels and onto small independent labels where it still thrives. These recent releases make the point. VARIOUS ARTISTS

"Out of the Darkness" (Fire on the Mountain 4001). Nine different acts from the leftist folk circuit contribute songs about nuclear power and weapons. The best songs are seductively understated: Pete Seeger sings a prescient 1945 talking blues, "Old Man Atom"; Kate Wolf sings the child- like parable "The Sun Is Burning"; Scotland's Dick Gaughan offers the traditional sounding "As I Walked on the Road." Rousing anthems are delivered by Sweet Honey in the Rock (the old hymn "Study War No More") and Cris Williamson (the familiar "Power"). By contrast, the contributions by Holly Near, Jesse Colin Young, Don Lange and Charlie King are clumsily didactic. HOLLY NEAR & INTI-ILLIMANI

"Sing to Me the Dream" (Redwood RR 407). Near, the popular peace and feminist singer, toured last spring with Inti-Illimani, the Chilean activist folk ensemble in exile. The Chileans played more than 20 folk instruments from the Andes with a virtuosity and rapport that challenged the operatic Near to ome of her best singing ever. Singing in English, Spanish and Quechua about hope and determination in the face of the junta, the performers blended the timeless airs of the mountains with the timely issues of today. GEORGE GRITZBACH

"All American Song" (Flying Fish FF 353). Gritzbach first made his mark as a sparkling blues and ragtime guitar picker, but he has matured into a sharp and witty songwriter. His slyly satirical songs about the nuclear freeze, creationism, American cars and meltdowns combine the irreverent spunk of an Arlo Guthrie with the splendid picking of a Chris Smither. Gritzbach also delivers poignant songs about lovers and children on this breakthrough album. UTAH PHILLIPS

"We Have Fed You All a Thousand Years" (Philo 1076). When the Industrial Workers of the World, the "Wobblies," organized workers in the early years of this century, their most potent weapons were often their songbooks. Veteran folksinger Phillips was a Wobblie activist in the Northwest, where he learned those songs, often simple satirical lyrics put to old hymn melodies. He recorded 18 of them for this live album; if the songs aren't very sophisticated, they're amusing, valuable history. REEL WORLD

"In Good Time" (Flying Fish FF 335). This all-female bluegrass quartet from Kentucky combines respectable picking with four-part harmonies. The group's biggest asset, though, is guitarist Beverly Futrell's songwriting, which brings to life such folks as Harlan County coal miners, a bayou matriarch, a sidewalk bag lady and a suffocating housewife. Futrell's sense of irony and detail are fleshed out by the band's steady ensemble playing. PAT SCANLON & THE BLACK WATER STRING BAND

"Songs for Future Generations" (Rounder 4016). The Greenpeace Organization sponsored this album by the Massachusetts bluegrass band. Unfortunately, these songs about nuclear power, the environment and war are full of the know-it-all smugness and bald sloganeering that give political folk music a bad name.