Dave Carter goes for symbolism. Open up any of his songs, and it’s like walking into a New Age shop from which all the unicorns have been exorcised. The Texas- and Oklahoma-raised son of an evangelist and an engineer, himself a mysticism student and road-tripper, Carter boasted a biography appropriate to his music—right down to the sudden death in mid-folk-festival season 2002, musically ageless but far too young at 49. He lived—and died—the sort of transcendental blues he sang and played.

Gathering the bits left over after the loss of a loved one can result in disappointment: Sometimes material remains in the vaults for a reason. But Carter and his partner, Tracy Grammer, were at work on an album (much of which was a reworking of Carter’s first, long-ago solo recording) at the time of his death, so Seven Is the Number has more direction than many posthumous projects.

True, it’s less cohesive than the couple’s two masterpieces: 2000’s Tanglewood Tree, which started their rise to fame in new-folk circles, and 2001’s Drum Hat Buddha, which made those early accolades indelible. It’s closer to When I Go, the 1998 album in which Grammer was still a “with” and not yet an “and.” On that disc, the collaboration was tentative; here, much of it has to cross the barrier of death itself, and Grammer too often ducks under her partner’s mighty shadow.

That said, if you don’t know what you’re missing, you’ll get another rousing testimony to the peculiar power of folk’s finest shaman/showman. The title tune, wound through with Grammer’s sinuous violin, typifies Carter’s ability to synthesize clichés (“High is the mountain/Deep is the sea”) and mysticism (here an inscrutable and ultimately inessential numerology) with engaging melody, creating something as far beyond the elements themselves as a hurricane is beyond dirt and water.

“Snake-Handlin’ Man”—its title perilously close to self-parody—goes balls-out, with Carter’s guitar teasing flamenco out of blues and his unpretty Texas twang throbbing as urgently as a panic attack. If he knows those snakes are powerful phallic symbols, he doesn’t feel the need to spell it out; he just grasps and wields one holy roller’s tool after another: poisons and tongues and the mighty Jordan, all in the service of winning your soul—and sister, you’ll give it to him. “Workin’ for Jesus” uses some of the same evangelical fabric in a very different way: The narrator’s love has left him to follow a religious crusade, perhaps against abortion (“She invokes the turtle dove, she awaits the number 9”), and his powers of observation (“She’s a little overdressed”) just barely pull him out of his melancholy.

A lot of Seven’s treasure lies in the unexpected. Carter often said his songs came from dreams, and this one begins with a doze on the couch that soon becomes a bright little spoken-sung trip to hell, where, old Nick says, “We got a barbecue all year ’round/Smokin’ little band with a country sound.” Big crowd, too: “Lawyers and thieves and state police, gentlemen of the press/Cons and flunkies, slackers, junkies, agents of the IRS.” Apparently, this place way down south, like Carter’s humor, can get “a mite dry,” but “we like it like that.”

If hick jokes don’t work for you, there’s the astonishing “Red (Elegy),” a song Kelly Joe Phelps probably wishes he’d written. The chorus is an incantation of loss, Donny Wright’s bass is the thrumming of a very faint heartbeat, Grammer’s violin is clotted with resin and tears, and—amid what seems a near-suicidal bout with depression (“Mama’s in the corn, and the fields are barren/Roof needs fixin’, but I’m way past carin’”)—as Carter’s subject cleans his gun, he looks at the TV and sees Fred Rogers: “Friendliest sucker I ever seen/We are precious in his sight.” That, right there, is the fruit of a pretty gnarly tree.