An obsession with sex and death underlies many of the immortal works of 19th-century classical ballet. Giselle is seduced, La Sylphide does the seducing, the Sleeping Beauty is awakened by sex, the Swan Queen is an apparition of death to Prince Siegfried who is easily waylaid by her doppelgänger, Odile of the 32 fouettées. Roland Petit brought it all out in the open with his ballets in the next century. As one observer said in 1949 of the premiere in London of his ballet Carmen, you could see the men’s trouser buttons popping.

Roland Petit died this morning aged 87, a world choreographer of chic and erotic theatricality who blew away the French classical ideal in a roar of post-war sexual liberation. He created an all-male corps of swans for Swan Lake long before Matthew Bourne, and his roles for his exquisite wife, Zizi Jeanmaire, repositioned ballet drama upon the femme fatale rather than the virgin. Arguably, though, for British ballet-goers he was above all the seducer who almost lured Margot Fonteyn away to France (and who got her to have a nose job) just as she was leading the Sadler’s Wells Ballet to international glory. Had Fonteyn done so, the history of Britain’s ballet would have been different.

Mark Twain once wrote of his experience of going to German opera. It starts at 6, he said, and they sing for four hours. Then you look at your watch, and it’s 6.15. This is also an all-too-accurate description of a night at English National Ballet’s Strictly Gershwin. Except that I began to look at my watch after 10 minutes.

Old-fashioned ballroom sequins have Derek Deane fatally in thrall

As everyone who has been watching Agony & Ecstasy: A Year with the English National Ballet on BBC Four now knows, Vadim Muntagirov, last night’s Prince Siegfried, and Daria Klimentová, his Odette/Odile, are the ultimate in ballet melodrama: one is a young dancer on the rise, the other reaching the end of a notable career. And both came together to produce a memorable Swan Lake in Derek Deane’s tasteful proscenium production.

At the 11th hour (as we all know from the current telly series), English National Ballet has pulled a gorgeous plum out of its back catalogue that throws open vistas of what a ballet company should be: Serge Lifar’s sumptuous Suite en Blanc. Why this beauty, laced with the hot Spanish deliciousness of Eduard Lalo’s 1881 music, hasn’t been done for 35 years can presumably be put down to its sheer difficulty, because this is a ballet that bathes the eyes in lipsmackingly tricky, astronomically stylish choreography - stylish as only French classical ballet can be.

You thought Black Swan was a nightmare depiction of the ballet world? Now watch Agony & Ecstasy: A Year With English National Ballet, Part 1 and squirm. Compare Natalie Portman’s tormenting balletmaster with ENB’s Derek Deane, as each of them stages Swan Lake. One tells his ballerina she’ll need to masturbate to discover her inner black swan; the other one contemptuously dismisses his ballerina as too old, too knackered, past hope.

Colin Jones was part of a legendarily painful triangle. Married to one of the greatest of ballerinas, Lynn Seymour, but constantly edged aside by the brilliant choreographer who was obsessed with her, Kenneth MacMillan, Jones left ballet to become a photographer, and used his unique access and friendships with people such as Rudolf Nureyev to document in unheard-of intimacy and freshness the golden era of the Royal Ballet.

Rudy and Margot do intensely serious barre in an Italian garden, Lynn Seymour enjoys a "Loyal Ballet" poster on a 1962 Japanese tour, in Glasgow two ballet girls snatch some rest in uncomfortable chairs. The real world of ballet, as shot by the insider who became a world photographer, Colin Jones. Read the interview with him, describing the friendships and tragic dramas behind the exhibition of 50 years of his ballet pictures at Proud Chelsea Gallery - events as turbulent as anything onstage.

English National Ballet's 2011 season listings pivot largely on the populist Strictly Gershwin dansical before returning to The Nutcracker for next Christmas. In between there are two intriguing programmes given brief but welcome London viewings, highlighting two French masters almost never shown in the UK, Roland Petit and Serge Lifar. Both were young radicals in their time, Lifar as Diaghilev's star who went on to lead Paris Opera Ballet, and Petit, the post-war rebel who oozed French chic, sexuality and modern style in his ballets.

The lighting chief holds the success of a magical fairy-tale staging in his hands. Whatever the designer has done, however fantastical and virtuosic his visions, the lighting chief can ruin it. So it is with English National Ballet’s new Nutcracker, in which two gigantic miscalculations kill any of its old-fashioned atmosphere. Act One is hobbled by a gauze dropped over the front of the stage for half of it; Act Two is sabotaged by ultra-violet lighting like a morgue fridge in a horror movie.