Captured in monochromes ranging from the most delicate honeyed golds to robust gradations of aubergine and deep brown, the earliest photographs still provoke a shiver of surprise and excitement. Even now, their very existence seems miraculous, and the blur of a face, or the lost swish of a horse’s tail signifies the photographer’s pitched battle with time, never quite managing to make it stop altogether.

After 16 years one might expect a revival of a repertory opera like Hansel and Gretel to come up with a dusty look and frayed edges. But Benjamin Davis has done a brilliant job pumping the life back into Richard Jones’s memorable but intricate 1998 staging of Humperdinck’s pocket Wagnerian masterpiece.

Even in a big orchestral concert, you’re bound to note Berlin Philharmonic principals as among the best instrumentalists in the world. I cited five in the central instalment of Simon Rattle’s Sibelius cycle on Wednesday. Of those, only viola-player Amihai Grosz figured in the Octet, joined by seven more players of peerless sophistication. Rattle may have been taking the evening off – unless he was brainstorming plans for a new concert hall elsewhere in London – and the keynote here was freed-up enjoyment.

Alice is always with us; the most quoted work of literature, after the Bible and Shakespeare. In fact, Desert Island Discs should probably add Alice to the mandatory Bible and Shakespeare as an automatic inclusion for the survival kit.

The habit among ballet critics of being simultaneously down on John Cranko's 1965 Onegin and up on Kenneth MacMillan's 1974 Manon is a curious one. The two have many similarities, from their basis in novels that became operas (though Prévost's Manon Lescaut antedates Pushkin's verse Eugene Onegin by a century), through their patched-together scores that don't actually use the Massenet/Tchaikovsky operas, to the knotty questions of morality and culpability that attend their titular characters.

What kind of regime, asks Gérard, talks of justice while killing poets? It’s a question the answer to which suggests itself all too swiftly this week, briefly turning a revolutionary romp of an opera into something rather more chilling. Playing things straight in his new production of Andrea Chénier (if wigs and lavender stockings, chandeliers and pastoral divertissements can be called straight), David McVicar may have missed a trick with a story that speaks with surprising clarity about the violence of political and ideological conflict. Or maybe he didn’t.

Ian Bostridge’s relationship with Schubert’s song-cycle Winterreise goes back 30 years. Many of those years have been spent in the public eye (and ear), allowing us to watch the tenor grow and grow-up with this music. It’s been over a decade since his first recording of the cycle with Leif Ove Andsnes, and almost that long since David Alden’s filmed version; the Bostridge who tours the cycle with Thomas Adès this year is quite a different singer and performer.

“A link in the chain of beauty” – that’s how the choreographer August Bournonville, in the 1840s, wanted every dancer in the Royal Danish Ballet to regard their art. And, remarkably, the chain of beauty we now call the Bournonville style has remained unbroken ever since. For complex reasons of politics and geography, as well as national personality, no doubt, while Romantic ballet in the rest of Europe fell under the spell of flashier Russian developments, the aesthetic Bournonville cultivated in Copenhagen remained impervious, in a little bubble of its own.

Youth may have vanished from the title, and its first flush is gone from the cheeks of most of the young persons. Now they’re in their prime, a magnificent sight – and the sound, too, is that of a world-class orchestra with a voice. Which we heard at its most distinctive, deep and muscular, from the strings in the opening signals of Beethoven’s Fifth Symphony. So what went wrong with the music from Wagner’s Ring in their first 2015 Southbank concert’s second half?

The twelve days of Christmas may be over, but I have good news for ballet fans in London: a whole new batch of presents for you has washed up at the Coliseum, and it's overflowing with lords-a-leaping, ladies dancing, and swans-a-swimming.