Romeo and Juliet, Royal Ballet

There are times when critics sheathe their quill tips, others when they don’t. Rupert Pennefather, the tall blond Englishman who has been earnestly promoted by the Royal Ballet as hard as they can to be the next Jonathan Cope, has attracted some devastating notices, and last night’s emergency outing as Romeo isn’t going to fatten his cuttings file.

This new run of MacMillan’s feverish Romeo and Juliet was intended to open with the famed partnership of Tamara Rojo and Carlos Acosta, heading a rousing supporting cast. But Acosta was injured, and instead up stepped Pennefather, and never before would a Juliet need to cry so feelingly, “Wherefore art thou Romeo?”

It’s hard on Pennefather, because Romeo is a huge role with at least four big solo sections which if a chap can’t pirouette easily, turn out his legs smartly, point his feet properly, and jump high and handsome, he isn't going to persuade us with a boyish smile and a look of doggy devotion. Pennefather once, under the expert tutelage of Johan Kobborg, delivered a very promising James in La Sylphide, full of fleet skips and footbeats, but Romeo needs masterly adagio control and the dramatic charisma of a really first-class actor. So it was difficult to understand this casting, especially subbing for the magnetic Acosta.

It was also hard on his Juliet, the ever-fascinating Tamara Rojo, who had to dance for two, and love for two, and die for two, and make us all weep for two, one of whom was a stick. The black-haired Rojo, the mistress of the stage and all the arts of ballerinadom, is the Juliet of our era. Her portrayal is uniquely fresh - she incarnates something lost in most modern portrayals of Juliet, she offers a throwback to what Juliet could have been five centuries ago. This is not a teenaged girl ready for boys, but a sheltered 14-year-old child who starts unmarked and unaware playing dolls with her nurse, and a few days later is screaming in agonised love in a mausoleum, clutching her boy lover’s corpse to her before unhesitatingly stabbing herself to death.

Rojo's genius is that she plays the part with no hindsight whatever - events gradually imprint their terrible consequences on her virginal character, they rip the protection of childhood off her, reveal this volcanically passionate and single-minded girl in love. Such an advocate is she that she almost convinced me that Pennefather’s wussy Romeo could be the cause of such an unguarded, utterly committed love.

But all around Pennefather’s blundering solos last night was an admirably keen-edged male line-up - José Martin, bold and playful as Mercutio, young Sergei Polunin an elegant yet focused Benvolio (Romeo material definitely), Gary Avis an irascible, battle-scarred Tybalt. Martin in particular has the leg spring to power those sharp knee angles and horsey prancing steps that MacMillan hands out to the men. Alastair Marriott held the stage subtly in his small role as Friar Laurence, and among the women Laura Morera was a redheaded firebrand as lead tart, while the beauteous Elizabeth McGorian always gives Lady Capulet’s keening over Tybalt the necessary ugliness.

Perhaps it was bad acoustics where I was sitting, rear right, but some unpredictable and unwelcome miking seemed to be going on in the pit, with second violins sounding from the right, and solo instruments oddly prominent. EU regulations have rated Romeo and Juliet a dangerously loud score for orchestras to play - are mikes and amplifiers being used to compensate? [IB adds: Barry Wordsworth, the Royal Ballet music director, notes below that there is no amplification, so I must presume this was an acoustics vagary.]

The Mariinsky Ballet’s Boris Gruzin frequently flies over to conduct the Prokofiev for the Royal Ballet, and like several Russian conductors of this ballet can be especially gripping in the action music and ensemble dances - last night Act 1’s opening scene was vigorously alert and dramatic. But, as I’ve noticed before with him, in the more personal scenes (Juliet’s ballroom duet with Paris, the bedroom pas de deux) his tempi were so changeable that they made the dancers look uncomfortable. Possibly the Russians' own iconic Lavrovsky version of Romeo and Juliet watermarks their instincts for the tempi, rather than MacMillan’s, which generally demands a little more pace and heedlessness.

After all it’s surely the recklessness of the youngsters as portrayed so brilliantly by MacMillan, the all-consuming immolation in love, that ensures that nearly half a century after its premiere this ballet still goes out and tells the truth every night.

• Book for Romeo and Juliet performances at the Royal Opera House until 16 March.
• Check out what's on in the Royal Ballet 2009-10 season
• See what's on at the Royal Ballet in 2010-11
• Read more Royal Ballet reviews