The Sleeping Beauty, Royal Opera House, London Manon, Royal Opera House, London

The best old ballets are like Dickens and Shakespeare: not only do they bear revisiting an indefinite number of times, but they have the capacity to yield more in steady increments.

Once, I'm faintly ashamed to say, I found it baffling that grown-ups would pay money to sit through The Sleeping Beauty, an elaborate late-19th century pageant stuffed with fairies and princes and people pretending to be rats and birds, created to flatter Russia's Tsar. Now that I've lost count of the productions I've seen of it, though, the memory of the best beams brighter than almost anything in 20 years of committed dance watching.

The Royal Ballet's current Beauty is an especially multi-layered thing, being a homage to the 1946 production that re-opened the darkened Royal Opera House after the Second World War. Given the privations of the time its glamour was a triumph in itself (some of Oliver Messel's costumes had to be fashioned from old curtains), but the ballet's themes – goodness vanquishing evil, the restoration of balance after a long trauma, the investment of hope in the unsullied young – were overwhelmingly apt. It still brings a lump to my throat to think of this staging's first reception.

But the main reason ballet companies, and the Royal in particular, can't leave Petipa's Sleeping Beauty dozing in the back-catalogue is that it offers more roles than any other dancework ever – and more technical challenge, more fizzing invention, more steps full stop. It is this, as well as Tchaikovsky's most dazzling ballet score – that keeps audiences coming back for a repeat of the buzz.

You can trace the arc of a ballerina's career through her Aurora, too. Sarah Lamb, the Royal Ballet's closest approximation to a porcelain shepherdess and almost of a size to pop on the mantelpiece, heads the first cast of this latest revival. Compared with her last-but-one outing in the role, she has come a long way. Not that she was ever unsteady in the famously testing Rose Adage balances, as the teenage princess is obliged to balance on one toe, lifted leg untiringly held and bent at a perfect 90-degree angle, while being passed perilously from hand to hand by a line of suitors. Now, though, she finds more space, more clarity, more obvious delight, in the flexible, almost ad lib moments when not only the conductor and solo violin, but every last member of the audience attends the next flexing of her wrist or pawing of her silk-slippered foot with inheld breath.

And has any girl ever whipped herself in and out of those plunging fishdives – one outstretched hand almost grazing the floor, the rest of her a perfect crescent – more deftly? In this she is abetted by superb partnering from Steven McRae, a peas-in-pod match not just in complexion and physique, but also speed, lightness and exactitude.

Of the music, you can tell how highly the players rate the score from the energy and care they lavish on it. Yet this is music written to order, chunk by chunk (when asked for 32 bars of music to accompany women knitting, Tchai-kovsky happily and wittily obliged): proof if any were needed that true genius rises to a challenge.

It's the absence of any such bracing element that makes Manon a lesser experience. For all its silky Massenet tunes, filleted partly from other ballet scores, it is a Classic FM mongrel to Tchaikovsky's thoroughbred. The choreography, made by Kenneth MacMillan in the early 1970s, is erratic in tone, classical-lite in its sometimes pointless leapings and twirlings, strikingly expressionist as a shipload of half-dead female convicts offer a disturbing vision of formalised reeling and fainting (you feel this is the ballet MacMillan would rather have made). Yet the story romps along perfectly well, and Sarah Lamb is again delicious in the title role. Even so, Manon is a heroine as venal as she is pretty, and so compliant in her downfall at the hands of unsavoury old men that you can hardly call it a tragedy.

'The Sleeping Beauty' to 21 Dec; 'Manon' to 26 Nov (both 020-7304 4000)

Next Week:

Jenny Gilbert seeks light and shadow in Caravaggio: Exile and Death

Dance Choice

Drawing on disciplines as diverse as ballet, martial arts, meditation and chi kung, Cloud Gate Dance Theatre of Taiwan returns with its latest work White. Divided into three acts, each presenting a different "white", the show plays with perceptions of light and presents the body in its purest form. At Sadler's Wells, London (Wed to Sat).