Comedian Eddie Izzard does a hilarious skit about Engelbert Humperdinck (aka Gerry Dorsey), the Anglo-Indian crooner who topped the UK charts in the 1960s.

Izzard imagines the singer's managers going through a whole list of crazy pseudonyms, such as "Zinglebert Bembledack" and "Yingybert Bangydan" before they finally alight upon the stage name "Engelbert Humperdinck". The truth of the transformation is, sadly, much more prosaic: Dorsey and his managers simply borrowed the name from the composer of the late 19th-century German opera, Hansel and Gretel.

The only conceivable reason for Dorsey taking on the composer's name is its striking memorability. It is hard to imagine it being a matter of musical admiration. There is, as I discover during a rehearsal of the opera at Scottish Opera's Glasgow HQ, precious little to connect the cheesy strains of Please Release Me (And Let Me Love Again) with an opera which was described by its first conductor, Richard Strauss, as "a masterpiece of the highest quality".

Strauss's enthusiasm for the score has been borne out in the century and more since the opera's premiere in the German city of Weimar in 1893. The bold confidence of the music, which is simultaneously majestic and beautifully attuned to German folk traditions, combines with the captivating symbolism of the Grimm Brothers' story to make this a much-loved part of the operatic repertoire.

So much so, in fact, that director Bill Bankes-Jones, founder and artistic director of acclaimed contemporary opera company Tête À Tête, felt the need to revisit the history of the piece in production. I meet Bankes-Jones at Scottish Opera's rehearsal room before we move on to Glasgow's Theatre Royal, where the set is being constructed for the opening performances. Along the way, he explains why he has written the first new libretto for the opera in quarter of a century.

"It's crying out to be done faithfully," he says. "You're forever seeing productions in which witches are jumping into microwaves and things like that."

Such self-conscious modernisations of the opera are, Bankes-Jones believes, largely a consequence of David Pountney's famous version for English National Opera in 1987: "It was all to do with the 1950s, suburban British childhood and nostalgia and yearning for that.

"So, it's very interventionist. The words are all about shepherd's pie and black forest gateau. He's being very witty."

So, while the director shares Pountney's desire to present the opera in English, and likes his predecessor's libretto very much, it is, he feels, "entirely specific to his wonderful production".

Looking back to early librettos, Bankes-Jones found that they were "very archaic. People utter things that human beings never say." There was, he remembers, quite an interesting moment at the start of rehearsals when Ailish Tynan, the Irish soprano who is playing Gretel (a role for which she received many plaudits in the Royal Opera's production of 2010-11), asked the director, "Can I sing, 'with stinky boys I will not dance'?" Bankes-Jones replied, "No you can't, because no eight-year-old girl is ever going to say that. It has to be 'I will not dance with stinky boys', and then I believe you're a real person."

"The singers get so used to doing this opera, and doing it in German," continues the director. His intention, however, was to do something rather paradoxical, to "make something that was faithful to the original" and to create a libretto which was "direct" and naturalistic for a contemporary audience.

Back in the rehearsal room, there is abundant evidence that he has achieved this. The striking Welsh mezzo-soprano Leah-Marian Jones, who plays The Witch, sings of her "intensive farming" of the hapless Hansel. It is a neat and modern intervention on Bankes-Jones's part, and combines strangely well with her casting a spell in English borrowed from Shakespeare. "Double, double toil and trouble/ Fire burn, and caldron bubble", she sings, from Macbeth, as she torments the children.

"It's meant to be a nod to Scotland, in a sort of playful way," the director explains, "because Macbeth is the Scottish play." Not that he takes credit for what is a really lovely idea. The use of Shakespeare's lines was, he says, hit upon by his 22-year-old godson. "The Witch casting a spell in English fits the music, and it's a little, token nod to Scotland. However, what I feel is really exciting is that I know that, if I sat and watched it, I'd go, 'oh my God, it's her!' And then you realise she's been in the bloody forest for 900 years, boiling children and interfering in Macbeth's life, and all that."

Bankes-Jones feels that Humperdinck's characterisations were of great assistance as he set about writing his libretto. "Gretel is very sophisticated," he says.

"She's endlessly introducing words. At one moment she'll say, 'this must be a confectioner's house', and, at another, the angels are 'illuminating'. Although she's the younger one, she's also the brainy one. She's a bit like Roald Dahl's Matilda in that way."

In contrast, he notes, "Hansel's language is fabulously monosyllabic. It's a lovely way to help a mature woman [Estonian mezzo-soprano Kai Rüütel] be a little boy. She has to say things like, 'I'm far too tough for that'."

The almost folksy, sing-songy aspect to much of the opera, and its preference for songs over spoken or sung dialogue, also has the contrary effect of heightening the realism of the piece. "Most of the language is songs," Bankes-Jones observes. "What's noticeable is the amazing naturalism that gives it. It's quite uncanny. People laugh at opera because they think it's weird for people to sing 'pass the sauce' or whatever. That doesn't happen in this, because, within their world, they're always singing a song about a mushroom or something."

The defiant, fairytale otherworldliness of the Grimms' tale made it easy, he says, to go back to Humperdinck's original opera: "You don't need to patronise the audience. You don't need to think that people won't sit through it unless it has modern characters. It's fine to have these kind of mythic, fairytale archetypes. The audience will deal with that very well, and enjoy it hugely."

Sitting in the dress circle of the Theatre Royal, watching immense, over-sized, abstracted trees moving, like sinister pieces of Swedish furniture, in front of a tiny gingerbread house, one doesn't doubt audiences will fall for this production. From the libretto to the design, Bankes-Jones's production is shaping up to be a very smart combination of tradition and modernity. How does he account for his capacity to sense how to present this opera for contemporary audiences? "I think I owe a lot to the very large amount of new work that I've done, both plays and operas," he says. "The first time you do a new piece, you sit down and think, 'Well, what are they trying to do?'. I don't really find doing this opera any different."

Hansel and Gretel is at the Theatre Royal, Glasgow, February 4, 8, 10 and 12, and Edinburgh Festival Theatre, February 14, 16 and 18. For further information, visit www.scottishopera.org.uk