When the opening sound cue provokes spontaneous applause, one tends to sit up and take notice. So it was with the shrieking factory whistle that locked our heads and hearts into Theater Latté Da’s pulsing production of “Sweeney Todd: The Demon Barber of Fleet Street.” Peter Rothstein’s staging opened Saturday in the beautifully apt Ritz Theater in northeast Minneapolis.

That siren blast would punctuate the air many times as the man with the razor slashed his vengeful path through a London that had done him dirty. Rothstein has created a dark, dystopian world and music director Denise Prosek shows an unrelenting grasp of the idiosyncrasies of Stephen Sondheim’s score.

Scenic designer Kate Sutton-Johnson uses junk — corrugated tin, crumbled cinder blocks — and the bones of an old playground with the rope bridges, swing sets and monkey bars to convey a sense not only of decay but also a lost innocence. For once upon a time, the world was a happy place for Benjamin Barker, the naive barber who becomes Sweeney Todd.

Rothstein took a bit of a gamble on actor Mark Benninghofen in the lead role. This is his first musical — a bit like chewing off “King Lear” in your first Shakespeare. Benninghofen’s cadaverous glare, his swagger and the serrated edge of his voice convey a bitter soul who has turned heartbreak into vengeance. Benninghofen is an actor who sings, rather than a pure singer, so musical theater buffs might sniff. His singing is not effortless, though he makes notable impressions such as the ode to his razors, “My Friends.” Beyond that, Bennnghofen paints such a comprehensive picture through his voice and performance that he makes this a Sweeney worth seeing.

Benninghofen is matched in presence and command by Sally Wingert’s scratchy performance as Mrs. Lovett, the landlady who provides “Mr. T” — as she calls him — space for his lacerating barbershop. Wingert’s cackling Cockney sounds as if it has been fed through a meat grinder and the actor locates the frightened and devious heart of this frenetic character.

Together, the two are slightly magic, producing the kind of evening in the theater that has you imagining yourself years from now, content that you caught this gig.

Rothstein surrounds these two ragtails with gorgeous singers. Tyler Michaels — you might have heard of him — is the stick-thin street urchin Tobias Ragg, who comforts Lovett with the sweet “Not While I’m Around.” Matthew Rubbelke was entrusted with the loveliest melody in the show, “Johanna,” and he reckons it a song of great longing and sadness. Dominique Wooten as Beadle and James Ramlet as the evil Judge Turpin (the man who sent Benjamin Barker to a penal colony) team up as an impeccable high and low combination of voices. Sara Ochs’ Beggar Woman and Elizabeth Hawkinson’s Johanna provide glittering work in the higher registers.

Rothstein wrote in program notes that “Sweeney Todd” is his favorite musical. He and his collaborators treat it as such with a show that grabs you at the outset and refuses to let go until the last whistle is blown.