Sweeney Todd (Andrew Lloyd Baughman) and Mrs. Lovett (Nina Osegueda). (Brandon Penick Photography)

“There’s a hole in the world like a great black pit,” sings the vengeful barber of Stephen Sondheim’s “Sweeney Todd.” In Landless Theatre Company’s “prog-metal” version, Andrew Lloyd Baughman sings with the gravelly voice of Beelzebub while electric guitars chime in the background.

Playing Pirelli, Sweeney’s rival barber, Rob Bradley screeches high notes like the front man of a 1980s hair band. Nina Osegueda’s Mrs. Lovett woos Todd with a “By the Sea” that features sinister, jabbing bass lines and monstrous guitar chords.

It’s bloody interesting.

That doesn’t make this “Sweeney” (at the Atlas Performing Arts Center through this weekend) a satisfying show. The acting is highly variable, and the staging of this usually gripping thriller is rudimentary, despite spectacular jets of blood as Sweeney finds his calling. Landless had neither the inclination nor the permission to fiddle with anything other than the orchestrations, so the story and characters will be perfectly recognizable to buffs.

So will the melodies, with lyrics popping out in a sound mix that has vocals dominating the instruments. If you’re worried about guitars so amplified your ears will bleed, fear not. It’s the voices that are pumped to piercing.

Still, it’s to Landless’s credit that the performance isn’t reduced to “Shrieky Todd.” Baughman, the company’s producing artistic director, actually croons a lot of the brooding melodies as Todd, and he leaps octaves effectively during the wrathful “Epiphany.” Todd’s “Pretty Women” duet with Judge Turpin (Patrick M. Doneghy) is sung to shimmering, echoey guitars that wouldn’t be out of place in jazz clubs.

For this unusual musical occasion, Melissa Baughman’s direction sets a grim mood and gets out of the way. Jared Davis’s set on Atlas’s spacious Lang Theatre stage is a two-story stone ruin bathed in green light by Chris Holland; the goth costumes are by Devin Gaither. The acting seldom catches your fancy: This crew has been assembled chiefly to sing in a certain style. On that score, the assets include Osegueda’s dusky vibrato as Mrs. Lovett and some surprisingly fine high notes from Joe York as Beadle Bamford (whose barks and growls are grossly overdone whenever he speaks in the part).

The six-piece band beneath the stage is composed of piano (played by musical director Charles W. Johnson), synthesizer (Brandon Fullenkamp), lead guitar (Alex Vallejo), second guitar (Spencer Blevins), bass (Ray Shaw) and drums (John Maestri). The orchestrators — usually working individually song by song — are Johnson, Vallejo, Blevins, Shaw, Lance LaRue, Andrew Siddle and Andrew Lloyd Baughman, together billed as the Fleet Street Collective. These orchestrations are complicated, taking on unexpected syncopations and allowing guitars and keyboards to chunk-chunk-chunk or squeal away in different directions.

If you’re interested enough to look in on this “Sweeney,” you’ll find yourself leaning in to hear exactly what these instruments are doing — and you’ll likely leave a little frustrated at how hard it is to untangle, especially with the vocals so thoroughly on top of what’s going on. (Microphone trouble dogged Sunday’s performance.) That mix is understandable if you’re going to stage the show and play the tale. A concert was reportedly the first instinct, and that surely would have given this novel “Todd” a better hearing.

“Sweeney Todd,” music and lyrics by Stephen Sondheim, book by Hugh Wheeler. Directed by Melissa Baughman. Sound design, Jim Wauters. With Michael Cafarelli, Shaina Kuhn, Angeleaza Anderson, Dylan Ngo and Alexis Turbat. About 21/2 hours. Through Sunday at the Atlas Performing Arts Center, 1333 H Street NE. Call 202-399-7993 or visit www.atlasarts.org.