The Tsarina's Slippers, Royal Opera House, London <br/>Cecilia Bartoli/Il Giardino Armonico, Barbican Hall, London

A family show fails to live up to its sparkly promise at the Royal Opera House, but Bartoli is brilliant

For some women, it starts with ballet shoes. For others, it's the gleam of patent Mary Janes. In my case, it was a pair of silver stilettos, carefully preserved by my grandmother since the 1950s.

Most of us have fallen for impractical footwear at one point or another, that leather-scented, slippery-soled promise of a more glamorous life. My friend the Country Mouse has several decades of kitten heels and slingbacks, mules and platforms, all wrapped in tissue and stored in famous-name boxes. But she did not enjoy The Tsarina's Slippers and neither did I.

Cherevichki, to give Tchaikovsky's opera its proper name, best translates as "Little Boots". Adapted from Gogol's story, The Night Before Christmas, it was a flop in its first incarnation. Revised in 1885, it remains a flop, albeit one in which the genius of Onegin and The Queen of Spades can be heard fleetingly. Adrift in a sentimentalised vision of 18th-century rural Ukraine, Tchaikovsky veers between lending Gogol's characters a crude version of his own, peach-skinned sensibility and depicting them as Michelin-waisted minstrels of serfdom, too busy carolling and canoodling to consider revolt.

Aimed at a family audience, Francesca Zambello's flat-footed Royal Opera House production takes the opera at face value, without irony. A lot of money has been spent on Tatiana Noginova's costume designs and Mikhail Mokrov's sets, which resemble a pop-up book. There are two ballets choreographed by Alastair Marriott (the Ondine fantasy by the banks of the Dnepr and the Petipa routine in St Petersburg), a vast effigy of Catherine the Great, four Cossack dancers, six demons, a bear, a golden sledge in the shape of a slipper, more babushkas than you could shake a hammer and sickle at, and several child actors who are pushed to the front as a human shield against tepid applause.

In an age when even Basil Brush is spritzed with irony, this animated Christmas window display is anomalous. I'm not suggesting that a landscape of rusting tractors would be ideal for Covent Garden. But I bet that rural Ukraine is full of girls who dream of owning a pair of Jimmy Choos and I'm not convinced that Zambello understands what a potent symbol of aspiration shoes can be. Tucked up in her cosy cottage, Olga Guryakova's squally Oxana is a spoilt little madam whose Tatyana moment in Act IV comes too late to win our sympathy. Despatched to find the fantastical footwear, Vsevolod Grivnov's noisy Vakula is as graceless as his sweetheart is charmless: a grinning lunk I'd barely trust to buy his own socks. There's more warmth in Zambello's characterisation of Solokha (Larissa Diadkova) and the Devil (Maxim Mikhailov), though again the singing lacks charm and the sack-gag falls flat.

Vocally, the finest performance comes from Changhan Lim (Wood Goblin). Even Sergei Leiferkus (His Highness) seems to have coated his vocal cords with spray-starch, though the neo-classical court music allows the orchestra to play with delicacy under Mikhail Mokrov's otherwise merciless beat. Too often dismissed as the go-to person when you need to work with animals and children, Zambello has done some highly sophisticated work in the past. In The Tsarina's Slippers, however, she has underestimated the sophistication of even the youngest audience members.

Does Christian Louboutin do thigh-boots? A flash of scarlet sole as Cecilia Bartoli stamped her feet to the tempest of Porpora's "Come nave" indicated he might. Sweeping on to the Barbican stage in breeches and cape, this was the mezzo reborn as a castrato: mutilated model of virility, poignant muse, operatic hero and victim of a fetish for unbroken voices that is said to have resulted in as many as 4,000 castrations of pre-pubescent boys in one year.

Sacrificium, Bartoli's meticulously researched programme of music written for the castrati of Naples, traced the history of the castrato voice in showcase arias by Porpora, Graun, Caldara and Broschi, brother of the most famous castrato, Farinelli. Her technique now marinaded in historical treatises, Bartoli's tiny voice has receded, bird-like, into her throat; still exquisitely controlled, still dazzling in fioritura, the sobbing "Parto, ti lascio, o cara" still indefatigably sincere. The psychological aspects of this obsession are fascinating. But all the loneliness and triumph of one who can do nothing but sing was here, accompanied brilliantly by Il Giardino Armonico, and what ravishing music.

'The Tsarina's Slippers': (020-7304 4000) to 8 Dec