Giselle, Royal Ballet/ Swan Lake, Russian State Ballet of Siberia

The chasm between the top-class ballet available to London-area ballet-goers and the low-grade stuff peddled in the regions is the field where the battle to save ballet’s soul is nightly won or lost.

One can start with the productions: after all, with various casts on offer, of different levels of skill and art, it’s the production that for most people will dictate whether they go home impressed. A good production survives a poor cast: the Royal Ballet’s Giselle is one of the finest classical productions there is, its settings by John Macfarlane of marvellous autumnal outdoors spookiness and quaintness, Jennifer Tipton’s lighting as dappled and mysterious as could be desired in any tale of the supernatural, and its performers, from top to bottom of the cast, know what they’re doing and are coached to do it damn well so as to lure the audience into Giselle’s rustic, haunted world.

Both stories are tales of a single fatal day. Giselle takes place on the day of the vine harvest, when peasants celebrate with a day off, their masters take a festive day’s hunting, and the young Duke dresses himself as a peasant to amuse himself by seducing one of the village girls. But he picks the wrong girl: Giselle is blameless, sheltered and enchantingly sweet, and when his cover is blown by a forester, she breaks under his betrayal, and suddenly he feels conscience. The formerly carefree young lord sleeplessly ranges into the forest to find her grave, where he is seized by the ghosts of all the other, less forgiving Giselles in the world and forced to dance himself to death. His Giselle challenges the rules to help him beat off her vengeful sisters, and disappears while he survives to live in a new consciousness of his actions.

Odette/Odile’s duality is an endless mirror into female wishes as well as a mode to search the differences between spirituality and fantasy

Swan Lake is also the tale of one day in a young aristocrat’s life, but this time he is dead by the end of it. Trapped in dull court routine, with a dynastic marriage threatened, he escapes to the wild outdoors (or possibly his inner world) and encounters swans just as they are magically turning back into girls, briefly permitted release from their evil slavemaster’s daytime tyranny. The Prince and the swans’ Queen are two fugitives, attracted to each other. But the evil genius makes the young man forget his new love by fashioning a doppelganger to seduce him into betrayal. In this story deception costs the life of the young man, his attempt to re-avow his broken love to the Swan Queen not working to set evil to rights.

Arguably both sexes get the thick end of the moral accusations in both these stories: men are deceivers led by their desires, women let themselves too easily be seduced into their fantasies. However, there are far deeper complexities and truths too: Albrecht, while he may be too worldly to kill himself in remorse as Siegfried does in Swan Lake, is undoubtedly a wiser and sorrier man at dawn, and Giselle’s forgiveness of him once she so painfully reaches the other world is a beautiful reflection of the wholesale absorbency of utmost love. Siegfried’s deception has much to do with the oppression of material imperatives and the urge to seek interior imaginative places to go into, however dark. Odette/Odile’s duality, like the role of the Queen of the Wilis in Giselle, is an endless mirror into female wishes as well as a mode to search the differences between spirituality and fantasy.

These are so endlessly fascinating as themes of exploring human nature, one’s own and those other options that are offered by fine performers and productions, that they do explain at least in part why the New Theatre, Oxford was filled on Tuesday for the Siberian Ballet’s Swan Lake. But it was mortifying to hear from the very first notes such incompetent playing by the skeletal company orchestra (only 29 players in total), and to see from curtain-up performers of such half-baked technical and theatrical standards.

The designs are traditional, in a pop-up calendar way, rather than in creating an imagined place on stage (pictured right, the corps of swans in the original 1895 Swan Lake production) and the producer has edited and abridged the story, pasting things here and there, so that it will end with Odette sorrowing by the lake for the drowned Siegfried, with her opening music looping back in circular implications for the narrative. That this makes no sense when Rothbart is also dead by now is to be overlooked, along with the dismemberment of Tchaikovsky’s music both on the page and from the pit.

One supposes the seasoned public is also expected to be blind to the quality of dancing. The Siegfried was not, as billed, the victor of the promising-sounding All Russian Ballet Competition 2010, Dmitri Sobolevsky, but an apology for a dancer - Vyacheslav Kapustin, I was told by the management - girly, soft-legged and overpromoted in a manner that Les Ballets Trockadero de Monte Carlo are quite ruthless in parodying. I doubt young Ekaterina Bulgutova, cast as the Swan Queen, would get out of a British corps de ballet with her skills, though she does have one of those fine-boned Russian physiques that promise so much. A man sitting behind me was pointing out to his companion that Raymond Gubbay promotes this company's comprehensive UK tour: “So his name should guarantee good quality, shouldn't it? Because this isn’t good quality, is it?” I can't disagree. And I am sorry to say it, as I understand Siberia's problems from my recent visit to this company's base in Krasnoyarsk, but they should not be degrading their own aspirations or those of their paying audience by touring performances as bad as this one.

Polunin last night was the finest Albrecht I can think of having seen since Irek Mukhamedov 20 years ago

So last night, even to watch an uninteresting leading lady like Roberta Marquez as Giselle in Covent Garden was such a quantum leap upwards - given the scale difference in production and company values - that it seemed an undeserved blessing to see a fabulous male performance by a new young star.

You’ve heard my encomia for Sergei Polunin before as he climbs through the male repertoire. Albrecht is the pinnacle of classical male roles, not only for its dramatic demands but its relentless combination of featherlight partnering skills and highest solo virtuosity. Polunin last night was the finest Albrecht I can think of having seen in Britain since Irek Mukhamedov 20 years ago, much younger than the Russian was when he came to this production, but with a grandeur and solemn grace you see hardly anywhere in the world.

He is taller and finer-built than the great Mukhamedov, with long limbs, a heartrendingly craggy face, and high, shapely jumps that made me hold my breath while he finished them off with tapered elegance. While poor Marquez was giving the Mad Scene her all, one couldn’t not watch Polunin giving a mental scene of his own, a thin-skinned, naive Albrecht reacting twitch after twitch as conscience and shame poured into him. Perhaps he slightly overdid the final dramatic collapse as Albrecht faces his own death, but this was a young man’s fervour as he inhabited this supreme role, and in every way Polunin has become what one dreams of finding in a ballet artist: someone not only capable of breathtakingly perfected technical finesse but a magnetic and searching personality who promises to tell you new things each time about this familiar but shape-shifting art.

He was assisted in every last degree by a vibrant musical performance of Adam's watercoloured score under Koen Kessels’s baton, rich with frissons, hauntings, colour changes, emotional starts, narrative cliffhangers and dansante sweetness, crowned by a sumptuous viola soloist in Act Two.

• The Royal Ballet performs Giselle in repertoire at the Royal Opera House until 19 February
• See what's on at The Royal Ballet. Read Royal Ballet reviews on theartsdesk
  
• The Russian State Ballet of Siberia tours the UK to 1 April with a repertoire of their versions of familiar ballet classics