Il Divo Christmas, Hammersmith Apollo, London

I hope we can contribute tonight to you getting in the spirit of Christmas," smiles tenor Urs Bühler, with that gaze of a man who knows that Il Divo fans need little more than harmonious revamps to get them in the spirit of anything, really – especially if it's a middle-aged female who's joined in the festivities to soak in the glistening Spaniard Carlos Marín, who, when announcing that the quartet would be singing "Hallelujah", was promptly met by said fan's orgasmic "yes, yes, yes!", leaving the balcony in stitches.

As a product of Simon Cowell's enterprising conviction that classical music needed to be livened up with a pop sentiment, the multi-national Il Divo have succeeded in establishing themselves as a sexy, operatic quartet who've made classy a lot more accessible. The complication with that, of course, is that the concept toes the line between the insipid and the sincere, and a Christmas variety show would seem to have all the makings of that gooey stuff that could leave you violently ill around this time of year.

But the evening is only 30 per cent cheesy, as David Miller, Sebastien Izambard, Marí*and Bühler are genuinely majestic when presenting the likes of "Somewhere over the Rainbow", "Rejoice" and "Ava Maria", with the help of the Royal Philharmonic orchestra. The inclusion of Vanessa Mae is a nice coup, and her racy experimentalism livens up proceedings, balancing out the moments when the men just stand stiff-backed and smiling, as though they don't quite know what to do with themselves. Second guest Camilla Kerslake, the Gary Barlow signing who gushingly reminds us she's famous for singing on those Waitrose ads, is also as pleasant as her name suggests, and injects her own sense of Christmas cheer with a gorgeous take on "The First Noel".

At the top of the show, Miller admitted it was the first time the group have done this sort of Christmas gig, but nothing about the glitzy lights, lovely small talk, orchestral accompaniment – and at one point a bag piper – is on course to mediocrity, and a soaring encore of "Oh Come All Ye Faithful" evokes such a rapturous high, that something that looks suspiciously like a party dress gets tossed on to the stage. The fellas could have done with letting loose themselves, but they can't be accused of not making this season a little bit merrier.