The bayadere bears on her shoulder a vase of holy water, and the story of the ballet La bayadère is of her refusal to compromise. She could better her life in two political deals: become the high priest’s mistress, or later, when bitten by a poisonous snake, take the antidote and live on while watching her sworn lover marry the princess who he knows tried to murder her. She refuses both. She remains, morally, the vessel of a purity that it would kill her spirit to give up.

The Mariinsky Ballet has just completed a three-week season, with terrific highs (and the odd low). This was the 50th anniversary of the Mariinsky's (then Kirov's) first London visit, in 1961, and it is worth highlighting the role impresarios Victor and Lilian Hochhauser have played in the cultural life of London. They brought the Mariinsky to London in 1961, and, half a century later, they have once more given Londoners a summer of artistic richness, with 10 ballets, six choreographers and numerous casts. We owe a great deal to this extraordinary couple.

So, to work.

This week we've a glittering, shimmering ballet score with an aquatic theme, and a brilliant British pianist shows off his compositional skills. Plus, in a week where we all need cheering up, 20th-century music's scariest genius shows that he had a fully developed sense of humour.

What you see in the picture is the money shot, and yes, it's a miracle that you won't fully believe, even as you watch it. But there are plenty of other belief-defying miracles in the Guangdong Acrobats’ version of Swan Lake - just don’t make the mistake of calling it a ballet, especially not in earshot of the haute-couture Mariinsky Ballet, currently up the road at Covent Garden.

It is claimed that the philosopher GE Moore had a fantasy. After many years’ work, Tolstoy had finally finished War and Peace. Sonya had copied it out for the umpteenth time. The thing goes off to the printer. Peace reigns. And then, in the middle of the night, Tolstoy leaps out of bed, shrieking, “I forgot to put in a yacht race!”

Great Mariinsky ballerinas are a breed apart, even from Bolshoi women. They take the stage with a consciousness of entitlement that’s thrilling to watch, and when this almost sacred sense of mystique and grace instilled in St Petersburg comes with vivid expressive distinction too, then there really is nothing like it. Even if three American 20th-century ballets might not be thought the likeliest territory to make such discoveries, what a night for ballerinas last night was. Viktoria Terëshkina and Alina Somova are on their way to joining the peerless Uliana Lopatkina at the high table.

It is all too easy to be cynical about the ballet version of Don Quixote. With almost no part for the title character, it is a 19th-century Russian take on faux-Spanish dancing, a farce in which the barber Basilio longs for the charming Kitri, while her father wants her to marry a rich fop. As the Radio Times used to say, “Much hilarity ensues.”

Mikhail Fokine, choreographer to both West and East, looked forward and back, too. He studied in the old Imperial Theatre School when the tsars ruled Russia, and he was also Diaghilev’s creative genius at the Ballets Russes, moving dance into the 20th century before and after the Revolution. The Mariinsky, once his home, is a premier exponent of his multifaceted styles. 

For most dancers the first base is to get principal roles. For a star like Carlos Acosta, second base becomes urgent: to find the career path beyond classical ballet. Like Sylvie Guillem he seeks out a new contemporary dance path to fulfil, being still full of glorious physical vigour and still well under 40. But it turns out to be about wise investment.

Act IV is the core of Swan Lake. It doesn’t seem so theatrically, being a peculiar 20-minute bolt-on after an interval that frequently lasts longer than the act that follows. But musically it transcends everything that has gone before, its thready little waltz one of the most delicately tragic things Tchaikovsky ever wrote. And balletically, Lev Ivanov’s rigidly structured classicism draws viewers into the terrifying void that is death. While emotionally the frozen swan-maiden of Act II and the brazen strumpet of Act III here merge to create the incarnation of suffering woman.