Music Issue: Frequently name-checked artists Mary Lattimore and Jeff Zeigler step into the light.

Last Saturday, Mary Lattimore and Jeff Zeigler sat at opposite ends of the International House stage to perform a live soundtrack to Le Révélateur, director Philippe Garrel’s visually stunning, if insistently obfuscating, 1968 silent black-and-white film.

The plot, if you can call it that, involves a mother, father and son moping around a sparsely furnished house, traipsing along a wooded road and scrambling across a field as if pursued by some unseen predator. Throughout, Lattimore’s harp strings might plink like raindrops or creak like rotting doors. At one point, Zeigler lays down a plush bed of synthesizers then ruffles it with an insistent melodica. The music is mostly pretty and sometimes paranoid, a smart fit for this strange little movie.

“They had all dropped acid before they filmed it,” smiles Lattimore, resting post-show in the I-House lobby. “Well, except for the boy.”

“Maybe,” quips Zeigler.

At this moment, the two are fried, having just driven out to Chicago to do Le Révélateur, then booked it back home for the Philly performance. Their fates have been tied to this film since late last year, when Texas arts org Ballroom Marfa invited them to create a live score to a movie of their choice. Though Garrel had envisioned his film as a stark and silent experience, the now-66-year-old director granted Lattimore and Zeigler permission to do their thing.

There’s no denying it: Some parts of Le Révélateur are boring, but Zeigler says the moments when very little is happening can end up being the “most musically useful.” That’s when the duo can exercise its formidable chops.

No matter how many times she’s sat through it, Lattimore can’t help but watch while she plays. “Some of the scenes are so beautiful, like so crushingly beautiful, that it makes up for the boring bedroom scene or whatever. Like the swans coming in, and the couple running in the field with the boy, the tree scene, the tunnel …”

Talk to enough musicians in this town and certain names — producers, accompanists, artists-behind-the-artist types — keep coming up. Lattimore and Zeigler get name-checked a lot.

And no wonder: A classically trained harpist, Lattimore has toured and/or recorded with Sharon van Etten, Steve Gunn and Thurston Moore of Sonic Youth. The multi-instrumentalist and producer Zeigler, meanwhile, has worked with Purling Hiss, Nothing and Chris Forsyth (often at his home-base studio, Uniform Recording). Rock stars like Kurt Vile and Adam Granduciel of the War on Drugs rarely make it through an interview without mentioning their favorite shadowy supporters, Lattimore and Zeigler.

Recently the shadows have parted, however, thanks to the release of their first official duo LP, Slant of Light, on the Thrill Jockey label. Compared to their work on rock and folk records, it’s pretty esoteric, like their compositions for Le Révélateur, which inspired it. Everything’s instrumental and unpredictable, sometimes soothing and other times distinctly dissonant. The longest track is 12 minutes, which is pretty restrained for two musicians capable of lengthy cinematic gestures.

“It’s like a punk rock ambient record or something,” says Zeigler. It’s true: There is a punkish urgency and an economy at work here. Nothing repeats much on Slant of Light. Listeners are more likely to perk up than zone out.

The record and the film — these are the projects these two feel most comfortable doing. “Being in a band, to me, is kind of stifling,” Zeigler says. “This way is way more organic and flows in a way that’s really refreshing.”

Says Lattimore: “It’s about hanging out and just making something beautiful or weird or whatever. We don’t really need to be like superstars on the cover of Spin. It’s not really about our faces.”