Angela Gheorghiu/Marius Manea/Philharmonia Orchestra, Royal Festival Hall

For anyone wondering what on earth the Overture to Leonard Bernstein's Candide was doing at the start of this bizarre, rag-bag of an evening (there seemed to be no rhyme or reason for its presence) might I suggest that the inference may have been that "in the best of all possible worlds" (to quote Voltaire) Angela Gheorghiu would have been singing more than two (yes, two) arias in the official programme with two more tired old chestnuts added as encores.

What is it with this South Bank "International Voices" series? Little more than a week ago we sat through great swathes of ballet music before Renee Fleming even stepped on to the platform, now along comes Gheorghiu with her very own tenor in tow. No, not that tenor, not the husband (there are it seems irreconcilable differences in that department), but a young Romanian Marius Manea who by no stretch of the imagination could be regarded as an "international" voice. Sorry, but when you have paid up to £75 to see Gheorghiu in concert you don't expect her to be sharing the evening with a decidedly average singing partner. A duet or two, perhaps, but not a two-way split of everything on offer. One might applaud her generosity in showcasing a fellow Romanian but, frankly, not at our expense.

The evening didn't even begin with a solo number from La Gheorghiu but rather with the fleeting reunion duet from act three of Verdi's La Traviata, a number which frankly makes no dramatic or musical sense lifted from context in this way. And if Marius Manea's tenor made a rather dry first impression here (his oddly breathy mezza voce sounded decidedly unnatural) then the solo number which followed – "Salut! Demeure chaste et pure" from Gounod's Faust – was way off-beam in terms of style. A melting, elegant, legato is not just helpful but de rigueur in this repertoire and I’m afraid Manea’s coarse, stiffly phrased, efforts just wouldn’t do. The famously difficult top C only really works when floated meltingly in head-voice, not thundered effortfully as if one’s life and reputation depended on it. His Verdi (Rodolfo from Luisa Miller) was no better.

Each of the duets – from Donizetti's L'elisir d'amore and Mascagni's L'amico Fritz – brought its fair share of cheesy canoodling "business", he wooden and awkward (which actually worked quite well for Nemorino), she coyly flirtatious. It was a little like watching "Renee and Renato" (remember them?) perform their pop classic "Save Your Love".

But all the time one kept thinking "what is he doing here?" And had it even occurred to Gheorghiu that we might not share her enthusiasm for her "discovery". That he was so uninspiring only points to her innocence in such matters. Whichever way you look at it, the exercise misfired.

So how was the lady herself? Well, the frocks (three of them) told their own story and wouldn't have been out of place on Cher in Vegas. The voice, with its wonderful dusky colour, is special, of course, though the huge range of "Pleurez, pleurez mes yeux" from Massenet's Le Cid necessitated some dodgy gear shifts into pure chest. That they felt forced was a bit worrying. Amelia’s "Morro, ma prima in grazia" from Verdi's Un ballo in maschera delivered thrilling open-voiced climaxes but little emotional engagement. The heartache felt cosmetic.

But that's the problem with evenings like this: like so much paste jewellery, everything’s there for effect. And just as you can’t buy a great voice, you can't buy style, either.