Anyone staging a concert performance of an opera, or operetta or musical, or however you choose to describe Stephen Sondheim’s Sweeney Todd, should hurry to English National Opera for some hints. The schlocky vases of flowers on either side of the stage, the polished concert grand and sober 58-piece orchestra occupying the stage where you hoped you might see some action: all was perfectly judged for a dull evening. On filed the chorus, in a quasi strip-the-willow crisscross, followed by soloists clutching scores, wearing stiff clothes and coy “we’re sorry we can’t smile” expressions, as if readying themselves for Beethoven’s Ninth rather than a Broadway hit. “Oh no!” the inner soul was screaming as the lights went down.

You can sample two Sweeney Todds in London currently: Tooting Arts Club’s cheery version at Harrington’s Pie and Mash shop, reviewed by Susannah Clapp last week, and this new, more luxuriant, gravy-rich one starring two greats of opera and theatre, bass-baritone Bryn Terfel and actor of genius Emma Thompson. These glamorous names notwithstanding, I had the distinct impression Susannah’s pies were going to prove better than mine.

Then Terfel suddenly dropped his score. Emma Thompson shoved over then kicked her music stand. Everyone else followed suit. The flowers were knocked flying, the piano upturned and carried offstage at a sprint. We had been fooled. This bloodthirsty 1979 musical thriller – to use Sondheim’s description – burst into raucous life and a full, or fullish, semi-staging by Lonny Price, gorily lit by Mark Henderson, was under way.

First seen last year at the Lincoln Center, New York, this is the inaugural production in a new partnership between ENO and the GradeLinnit Company to stage musicals at the Coliseum. If the hope is to catch a theatre audience they succeeded – at least on Tuesday’s press night. How could I tell? There was a lot of noise in the foyer. Programmes were West End-style big, slim and glossy instead of the usual short, fat, learned operatic variety. Theatre critics, too, had been encouraged to review the show – presumably under some misapprehension that because the singers were amplified, we music aficionados might quail. On the contrary, for some music, some texts, it works. Sweeney Todd is one.

The Demon Barber of Fleet Street and his “business partner”, Mrs Lovett, Victorian penny dreadful characters, have little to commend them in human terms, but for reasons that can only be to do with their interesting non-vegan cuisine, they remain popular. He cuts (throats), she cooks. Her spewy, chewy, taste-the-difference pies feature in that dietary line stretching back to Shakespeare’s Titus Andronicus (pastry-encased sons eaten by their mother) via Hannibal-the-Cannibal Lecter and the delicious barbecued human ribs in Fannie Flagg’s novel Fried Green Tomatoes at the Whistle Stop Cafe.

If, somewhere in this poverty-stricken, rat-and-disease-crazed world of Victorian London, there’s a message about the degradation of the weak by the wealthy and powerful, now could hardly be a better time to think about it. Emma Thompson, quoted in the programme and having the time of her life, compares the story to the best of Dickens or Baudelaire, and notes of Mrs Lovett: “This woman has struggled all her life with pretty much everything. Now suddenly it looks like the golden prize has dripped into her lap – and then it’s snatched away in the most awful manner.”

It’s Lovett’s story almost more than Todd’s. Thompson, dressed in worn-out red tatters like a ditsy Kundry or, in her mad, tottering physicality, Poor Tom on the heath, sings with real musical confidence. Chest and head voice might have different colours but the brilliance of her timing, her sense of pitch, her clarity and understanding of each word make for a mesmerising performance. The patter, the homilies and truisms, the throwaway lines and witty asides are delivered impeccably.

As the lugubrious, intentionally stolid and morose Todd, Terfel is the perfect foil. He maintains absolute vocal control and physical stillness, and upstages no one. In Pretty Women, in Johanna, and so too in his own, final Ballad of Sweeney Todd, his voice is velvet smooth and beautiful, never awkward in the context of weaker members of the ensemble. He has electrifying presence and makes the rest of the West End cast – led by Katie Hall, Jack North, Philip Quast and Matthew Seadon-Young – seem better, bigger, more compelling. Yes, the singing was uneven, but Sondheim’s all-important, tongue-twisting lyrics were always audible. No doubt there will be much groaning about this whole meaty enterprise. Neither fish nor fowl but who cares. If it keeps ENO on its feet, I’m for it.

Congratulations to the Van Kuijk Quartet of France, £10,000 winners of the 13th Wigmore Hall international string quartet competition. In joint second place the USA’s Verona Quartet and the British Piatti Quartet are names to watch. Listening to six hours of Beethoven – the obligatory challenge for the two rounds of semi-finalists and pure pleasure given the exceptionally high standard of all involved – I had marked the Van Kuijk’s card from the start. Their Op 59 No 1 had style, energy, huge potential and, above all, a sense of risk – the absence of which alone pulled other excellent groups down, since technique or intonation were hardly ever an issue. These four young Frenchman made the music smile, and would have made Beethoven do the same.

Star ratings (out of 5)
Sweeney Todd ****
Wigmore Hall international string quartet competition *****

• Sweeney Todd is in rep at the Coliseum, London WC2 until 11 April