Fifteen or 20 years ago, the singer Josh Groban would have seemed well suited to perform in a production of “Sweeney Todd: The Demon Barber of Fleet Street” — but not in the title role. With his robust, limpid bari-tenor and mild, affable persona, Mr. Groban might have been a candidate for the role of Anthony, the male ingénue who rescues Sweeney while the latter is escaping from prison, then falls in love with his teenage daughter.

Although Mr. Groban is now in his 40s, the announcement that he would play the middle-aged protagonist in a new revival of Stephen Sondheim and Hugh Wheeler’s masterful thriller generated some skepticism. Vocally, the part is well within his range; but could an artist who was groomed by adult contemporary pop guru David Foster, and whose past projects have included corny classical crossover collaborations with the likes of Sarah Brightman and Charlotte Church, summon the savage wit and sheer rage required for Sweeney? Or the dark charisma required for this character, who seeks vengeance not only on the corrupt judge who unjustly jailed him but on all of humanity, eventually? 

The answers, as it turns out, are yes and yes. While Mr. Groban proved his stage acting chops in a vastly different role a few years ago, in the Broadway premiere of the musical “Natasha, Pierre & the Great Comet of 1812,” his Sweeney is more of a revelation, showing an agility and depth that should put any accusations of stunt casting to rest.

If director Thomas Kail’s production is less illuminating overall, that’s in part because it has a lot more history to compete with. Since its premiere in 1979, Sondheim and Wheeler’s spin on the tale of Sweeney Todd — based on playwright Christopher Bond’s adaptation of 19^th century fiction and legend, and originally helmed by Harold Prince — has been revived by high-profile directors and starry casts, in stagings ranging from concerts to full-scale operatic interpretations. 

No show has better captured the range of Sondheim’s genius; the melodies soar and pierce, their warmth and dissonant edges reinforced by Jonathan Tunick’s ravishing orchestrations, and the lyrics incorporate both some of Sondheim’s most dazzling wordplay and some of his simplest, most direct appeals to the heart.

Mr. Kail, who rose to prominence as Lin-Manuel Miranda’s collaborator on “In the Heights” and (especially) “Hamilton,” has enlisted noted choreographer Steven Hoggett, who has cast members physicalize these lyrics at times and generally seems intent on keeping their bodies moving as much as possible. Ensemble numbers, including “The Ballad of Sweeney Todd” and its intermittent mini-reprisals, are elaborately arranged, with actors swaying in unison or bobbing up and down. 

The effect can be, if not distracting, a little busy. Messrs. Hoggett and Kail do have a fortunate muse in Mr. Groban’s co-star, Annaleigh Ashford, who plays Sweeney’s adoring, amoral conspirator, Mrs. Lovett. A famously deft and enthusiastic comedic actress, Ms. Ashford enjoys a giddy pratfall within moments of her entrance, then relays her character’s abiding affection for Sweeney with nimble but seldom subtle motion, from kicking up her heels to the old bump and grind.

Ms. Ashford’s line delivery, dizzy and breezy on the surface but razor-sharp at its core, makes her a fine partner for Mr. Groban, whose performance reflects that for all of Sweeney’s brooding and seething, he can be opportunistically charming, and not entirely humorless. Teaming up for “A Little Priest,” the tour-de-force duet in which Sweeney and Mrs. Lovett imagine how his victims will taste in her meat pies — “Here’s a politician so oily it’s served with a doily,” she quips, to which he responds, “Put it on a bun/Well, you never know if it’s going to run” — the stars are so breathlessly, joyfully engaging that the horror of the scheme is nearly overshadowed.

The supporting players are also well cast. Jordan Fisher’s Anthony acts and sings a bit tentatively at first, but gains confidence while sustaining the character’s naivete and humility. Jamie Jackson, conversely, oozes arrogance and pretension as Judge Turpin, the “pious vulture of the law” who framed Sweeney in order to try to seduce his wife and now has designs on his daughter. 

Maria Bilbao makes a fetching Broadway debut in the latter role, Johanna, also Anthony’s love interest, whom the judge has kept locked in his home, as his ward, since destroying both her parents. Ms. Bilbao’s quivering presence and bright, slightly shrill lyric soprano convey the hint of madness necessary to play this caged bird effectively — just as John Rapson, as the judge’s obsequious beadle, brings the required comical unctuousness and keening tenor to that role.    

Young Broadway veteran and “Stranger Things” star Gaten Matarazzo gives the most heartrending performance, as Tobias, the street urchin who unluckily falls into Sweeney and Mrs. Lovett’s employ, but has the good fortune to sing one of Sondheim’s purest and most enduring ballads, “Not While I’m Around.” It’s a credit to everyone involved, from the unlikely but triumphant leading man to the potent-voiced chorus members to designers who make witty mischief of murder, that this “Sweeney Todd,” despite its imperfections, delivers the thrills, chills, and transcendent beauty that any production should and must.