Tackling one of musical theatre’s greatests well, greatest, can often prove a double-edged razor.

Pull it off, and the plaudit of ‘masterpiece’ is yours. Misfire – or even worse, miscast – and you risk a stagey hindenburg from audience expectation alone.

Of course, reviving Sondheim has never really been out of vogue. In recent years, the likes of Marianne Elliott’s gender-flipped Company, or Jordan Fein’s more sinister Into the Woods at the Bridge Theatre have scooped up audiences, critical acclaim and Oliviers alike.

Yet by any metric, a decadent, bombastic staging of one of his most ubiquitous hits, Sweeney Todd, is an ambitious undertaking as an in-house piece for the Birmingham Rep.

The first sign that Artistic Director Joe Murphy was onto a good thing came with the announcement of West End and Broadway favourite Ramin Karimloo as the titular antihero. Throw in an inspired but slightly out of left field choice for Mrs Lovett in international cabaret artist, Meow Meow, and multi-Olivier winner David Bedella poached as Judge Turpin, and if nothing else, audiences knew they were going to get vocals.

Perhaps the biggest and most welcome surprise then, is the grandiosity and sheer scale with which Murphy and his creative team have forged this Sweeney to meet the wattage of talent on stage.

Elin Steele’s imposing staging is a thing of stark, harsh monochrome majesty. A tapestry of Lucifer’s fall gives way to the ever-looming presence of a colossal Lady Justice, sitting centre in the Rep’s already sizeable stage. Here is a London akin to a grand, unyielding courtroom, with justice, revenge and judgement all bloodily intertwined. Morality is, naturally, various permeations of grey. And much of Rory Beaton’s haunting work underlights proceedings – not least of all the almost Brechtian chorus who intermittently chant Sondheim’s tale to the audience.

This is sweeping, operatic musical theatre of a scale and quality scarcely seen even in such established and excellent spaces as the Rep. The likes of which would not feel out of place in the likes of the London Coliseum.

“This is sweeping, operatic musical theatre of a scale and quality scarcely seen even in such established and excellent spaces as the Rep.”

For those unfamiliar with the broad strokes of Sweeney Todd’s tale, it is a ‘musical thriller’ following the thirst for revenge from a wrongly convicted barber (Ramin Karimloo), who returns to London in the hopes of reuniting with his family and righting those who wronged him. Unsurprisingly, things have changed during his fifteen years in the penal colonies, and the down-on-his-luck Todd ends up lodging, and later co-conspiring, with the eccentric Mrs Lovett (Meow Meow), proprietor of a shop selling ‘The Worst Pies in London’. Together, they settle upon a nefarious fusion of their purposes, as Todd begins providing customers with a barber’s visit so sharp they end up spiking the sales of Lovett’s baked horrors.

Widely regarded as one of Sondheim’s finest accomplishments – itself no faint praise – whilst many may be familiar with the 2007 Tim Burton film adaptation featuring Johnny Depp and Helena Bonham Carter, it is on the stage where Sweeney truly soars. Almost entirely musically underscored and featuring a bloody, funny lashing of complex characters, intricate storytelling and, naturally, fantastic songs, there’s no understating how good a quality production of Sweeney Todd can be.

The extra character beats afforded on stage (such as a truly repulsive solo number from Judge Turpin) are so viscerally leant into here by Murphy and the cast that it makes this iteration both lighter and darker at once. It is frequently funny, not least owing to some of the perfectly realised supporting turns such as Julius D’Silva’s scene-stealing, odious bootlick, Beadle Bamford, or Silas Wyatt-Barke as a venal rival barber. Jack Gibson delivers a beautiful renditon of young ‘Toby’s’ ‘Not Whilst I’m Around’, whilst Meow Meow is having tremendous fun throughout with a kaleidoscopic, whirlwind Mrs Lovett who runs the full gamut from eccentric to haunting and every shade in between. A quiet moment where she offers a glimpse at her true, pathetic self, hunched over and untangling her hairpiece, is masterful and unnerving in its simplicity and rawness; this opportunistic, manipulative devil exposed as just another broken shell pushed to ever more desperate measures.

At just shy of 3 hours, it’s a testimony to Murphy’s taut direction and the cast’s chemistry that the time flies by. For certain, there are places where sub-plots such as young sailor Anthony’s (a spirited Shem Omari Jones, in fine voice) longing for Todd’s stolen daughter Johanna (Jo Stephenson, also delivering beautiful vocals) can languish, or it serves up a reprise or incidental number that could probably be cut (pun intended) without the show suffering for it. But Murphy and company keep things moving (quite literally), with the excellent use of levels on Steele’s monolithic staging coupled, with the tremendous performances, meaning it all rarely lulls.

“His utterly roof-raising ‘Epiphany’ is a blistering reminder of just how good he is…”

Which leaves the tale of Sweeney Todd himself. Already a firm musical theatre favourite, Karimloo boasts the likes of Phantom, Miss Saigon and multiple roles in Les Mis on his MT rap sheet. He unsurprisingly takes to the conflicted rage and reserve, and booming baritone of Todd like a silver blade to the jugular. There is a stillness and dignity here, too, even a charm, to his murderous barber, one that makes the eventual eruptions of hatred and venom all the more shaking. His utterly roof-raising ‘Epiphany’ is a blistering reminder of just how good he is, and is one of many peaks of a titanic central turn.

So get Sondheim right and you have a surefire hit on your hands.

It’s a credo that Murphy and his team have ran with, serving up an epic, uncompromising, raw and full-throated Sweeney. Karimloo and Meow Meow more than earn their (mouldy, dry) crust, delivering a pair of knockout performances as fantastic as they are so perfectly, complementarily different, all encapsulated in a grand, grim playground of theatrical stagecraft.

If it’s a sumptuous evening of musical theatre you are after in Birmingham this Summer, you’ll find few better options, and no closer a shave, than this razor-sharp, funny and thrilling Sweeney Todd, the gleaming showstopper off Broad Street.