It’s the look that gets me. For 15 minutes Thomas Allen and I have been trading niceties. He’s reflective, genial – possibly even a trifle worthy. But then we hit on Don Giovanni and it’s all change. Suddenly Allen’s eyes glint with devilish glee. Not only does he speak with utter authority about the man, he practically becomes him. “It’s like a really good sauce,” Allen says about nailing the part. “If you reduce and reduce and reduce, and bring it right down to the absolute essence, then it’s overwhelmingly powerful.”

The relief is that the man who has sung the Don “something like” 300 times is keeping the association, despite having no confirmed plans to sing the role again. Building a second career as an opera director, Allen is now steering the Samling Foundation’s staging of Don Giovanni. And in something of a coup for the organisation, this production at the Sage Gateshead will also include the superb baritone Christopher Maltman making his role debut as the lascivious hero.

Allen is candid on the challenges of sitting in the director’s chair – a role he will again assume for Scottish Opera’s new Barber of Seville in November. “I’m constantly having to remind myself in rehearsal that if there’s nothing going on it’s because you’re not actually doing anything, and if it’s quiet it’s because you should be saying something. You’re the actual engine that makes this thing work.”

But as Maltman no doubt realises, there can be no better engine to motor Giovanni than Allen. And his enduring love of the part began with his very first stab at it, in Peter Hall’s acclaimed 1977 production at Glyndebourne. “He allowed that character to emerge,” Allen says. “And more than anything else I’ve ever done it felt as though it was something that was in me waiting to emerge.”

Did he like him? The eyes, which were flashing with the Don’s transfixing glare, suddenly sparkle with roguish charm. “You can’t help but like him. He’s got such daring and bravado and madness from one moment to the next. Even playing him you don’t know what’s going to come out next. I’ve already said to Chris [Maltman] that he should come in at every rehearsal and just surprise me. You should never know where you are with Don Giovanni.”

Allen admits that the Hall production set a template. “It’s sounds awfully glib and flippant to say it, but I really do believe that what I discovered through his production has been a common thread for me. But, of course, even if you get it right the first time you still have to keep on looking.”

In Allen’s case, that meant turning inward. “As time went by, the swashbuckler with the shirt cut to the navel disappeared, and he became darker and darker. Whether that was the ZeitgeistI don’t know – but one realised that the stiller one became the more powerful the man became.”

In the case of his British productions, that process culminated in Johannes Schaaf’s powerful (but not uncontroversial) production in Covent Garden, first performed for the Mozart 250 celebrations in 1992. “An ageing Prince of Darkness,” marvelled one national newspaper, “with thinning, slicked-back hair and the venomous charm of a viper.”

As for the Sage production, Allen is keeping his cards close to his chest. Fascinatingly, he hints that religion, and the piety of the Don’s victims, will play a part. “They all have that refuge, but he can’t go there, it’s a barrier for him.”

Most of all, however, this singer-actor wants to spark off his cast rather than impose a concept. “It’s a joint process, it’s not an imposition on the singer. It’s best when you start to invent and improvise.”

The great surprise of Allen’s career is that one of Britain’s best singer-actors had never set foot on stage until after his musical training. In Seaham, the small Durham mining town where he grew up – Billy Elliot was filmed in the next village – acting was sissy. “But there was no stigma attached to singing,” chuckles Allen, who began in the church choir and ended up, thanks to grammar school and a professor with a shared love of golf, at the Royal College of Music in London.

It’s the comparative humility of his origins that probably contributes to his loathing of overpromoted crossover artists. “They don’t sing opera, they don’t register on the scale at La Scala or the Paris Opera or the Met – these are the venues where you have to appear and where so many British singers have been appearing for a long time. Theyshould be getting the accolades.”

But he isn’t really so gruff. As well as directing the Samling productions, Allen has thrown himself into the foundation’s work with children, trying to dispel the myth of opera being “not for them”. And the metamorphosis into grizzled director is by no means comprehensive, either. In the next year he’ll be back at Covent Garden three times (for Così, The Magic Fluteand Ariadne auf Naxos), and in autumn 2008 another formidable Allen – Woody – will be directing the baritone’s first attempt at the title role in Puccini’s Gianni Schicchi in Los Angeles. “The R word – retirement – I detest. Your brain atrophies at the moment you take on the concept.”

But would he like to be the Don again? “I’ve no burning ambition to do anything now – except I still feel I want to sing Don Giovanni. It’s strange, but I think the man should go full span. You could well regard him as a hanger-on from another age who just walks into the room and distorts everything. He can do that.”

He gives a viperish grin. “That’s what he should do.”

— Don Giovanni, The Sage, Gateshead (0191-443 4661), Tuesday to Saturday

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