The staples of American folk music — acoustic guitars, baroque melodies, hippy poetry — have been so overused that they became clichés long ago. But lately a widening section of the rock underground has reworked these devices into original takes on musical history. Acts as diverse as warbling bard Devendra Banhart, Brit-folk revivalists Espers, and even raging rockers Comets on Fire have been lumped into this sprawling subgenre. Some call it “freak folk,” but the music is too substantial to be simply freaky and too diverse to be just folk.

The most interesting of these groups use folk and other genres as launching points, propelling them toward new forms. Two stellar examples are Charalambides and Wooden Wand, who will perform together (along with Zaimph, the solo project of Double Leopards’ Marcia Bassett) tomorrow at the Knitting Factory.

The longevity of Charalambides makes its members godparents to the avant-folk underground. The band began in Houston in 1991, built around Tom Carter’s exploratory guitar and Christina Carter’s haunting vocals. Fifteen years later, the group has undergone a series of major changes: The Carters divorced and moved to separate coasts, and a line of collaborators, including guitarist Jason Bill and pedalsteel player Heather Leigh Murray, have come and gone. Unsurprisingly, Charalambides’ musical output, which totals more than 23 albums to date, has constantly evolved.

Since 2003, Charalambides have recorded four albums for the Chicago label Kranky. The latest, “A Vintage Burden,” features the original duo alone and offers their most gentle, meditative pieces yet. On tracks like the floating “Hope Against Hope” and the achingly beautiful “Dormant Love,” Ms. Carter’s otherworldly voice drifts through Mr. Carter’s patient chords, forming the most hummable melodies the pair have ever written. Elsewhere, “Black Bed Blues” unfurls 17 minutes of wandering guitar duet, approximating the hypnotic psych-rock of bands like Bardo Pond or Acid Mothers Temple, but with a softer, dewier aura.

Aside from Charalambides’ ongoing ouevre, both Carters are prolific on their own. In the past year, Ms. Carter has issued two solo records — the ethereal “Electrice” on Kranky and the introspective “Lace Heart” on her own label, Many Breaths — and contributed to the acoustic guitar series “Imaginational Anthem.” Aside from his own solo projects, Mr. Carter maintains collaborations with Bassett, the Oakland duo Yellow Swans, and the Bay Area sound artist Robert Horton. Since passing time and increasing distance have yet to slow the Carters’ activity, it seems doubtful that anything will.

Not as old in musical years but just as prolific is Wooden Wand, the pseudonym of singer-songwriter James Jackson Toth. Mr. Toth began playing with the rotating collective Vanishing Voice in New York in the late 1990s, releasing four proper albums and a myriad of limitedrun releases. Those records explore rustic country, lonely folk, dense psych-rock, improvised experiments, and more. The common denominator is Mr. Toth’s wideopen curiosity, which turns simple song structures into raw explorations and impulsive excursions.

Recently, Mr. Toth has steered closer to traditional folk and blues, playing with many more musicians under a variety of group names. Earlier this year he crafted “Horus of the Horizon,” a mostly acoustic set of Dylan-esque ditties with the Omen Bones Band. More recently, he teamed with the Sky High Band, which includes members of the experimental collective Jewelled Antler, to concoct the swaggering, countrified “Second Attention.” Here, Mr. Toth boldly attempts to make a long-lost country-blues album. Recorded live on vintage equipment, the record’s strongest trait is its unabashed commitment to its genre.

Mr. Toth, whose twangy, nasal drawl recalls Robyn Hitchcock, Jack White, and even John Lennon, weaves simple yarns that burrow slyly into the brain. On “Portrait in the Clouds,” his musical comrades wrap his musings in affirmative backing vocals, fuzzy guitar, and warbling organ. “Crucifixion Pt. II” and “Madonna” dart around gospel-like figures and religious lyrics, and “Dead Sue” rides a swinging melody toward a dusty, sunset-drenched musical distance.

Perhaps Mr. Toth could be accused of co-opting traditional styles for his own needs rather than expanding them on “Second Attention.” But his sly sense of melody and enticing wordplay make such complaints seem as pointless as questioning whether Charalambides distort similar influences by taking them into uncharted territory. Either way, these two groups are carving distinctive paths, and the manipulation of folk tradition is just one tool in their impressively large arsenals.