The eel is dying. Its body flits through a series of complicated knots which become increasingly grotesque torques. Immersed in a pool of brine — concentrated salt water five times denser than seawater — it is succumbing to toxic shock. As biomatter on the sea floor of the Gulf of Mexico decomposes, brine and methane are produced, and where these saline pockets collect, nothing grows. Dead creatures drop into it; live creatures that linger in it die.

Watching tango dancers Gisela Galeassi and Nikito Cornejo own the apron of the stage during the second half of m¡longa, the brain finds it difficult to process what the eyes are seeing. The pair seem to be one writhing, dark-toned dervish of jutting, sensual, passionate movement. Back and forth they go, he spinning her round his body like a silk scarf, fluid as mercury; her feet attacking the stage, staccato, kicking out, kicking down, so fast it really is the proverbial blur. Nigh on two hours of tango with a 20-minute interval might sound like too much, but with only the smallest of lulls in interest, this show grips, from start to finish.

Belgian choreographer Sidi Larbi Cherkaoui’s international breakthrough was his award-winning 2008 collaboration, Sutra, with the artist Anthony Gormley and the Shaolin monks. He has since become a leading choreographer, always willing to explore global influences and sources. He’s revelled in the Hispanic before on the flamenco-themed Dunas, with Spanish dancer María Pagés but m¡longa is as very different affair, unwrapping the Argentinian tango and opening it out to a kind of visual concept album, based around six couples, coming together and apart, in different moods, in what we may imagine to be a Buenos Aires cityscape of streets, cafés and nightclubs.

The bandoneon-led sound of tango is an easy delight

As well as dancers, m¡longa utilises film and visuals to potent effect. There is a wonderful scene where a dancer stands with his back to us manipulating a giant screen of photos via gesture, like Tom Cruise in the film Minority Report. And another where dancers rush about trying to keep up with landscapes speeding past behind them, like Hollywood actors at the dawn of cinema comedy. On one occasion these visuals precede the show’s most enjoyable moment of outright clowning, when brightly auburn-haired dancer Vivana D’Attoma plays a woozy drunk, trying to pull the suavely dismissive, evening wear-clad Gabriel Bordon. Her floppy moves, precisely estimated, are a well-portrayed twist on the rest.

Some set pieces are isolated moments, such as the somehow shocking dance wherein Esther Garabali and Martin Epherra act out, via tango of course, an explosive relationship, bordering on the violent, or a sequence where three male dancers perform a particularly frantic, energetic routine. Other themes, however, run throughout, interspersed with the rest of the action. Particularly notable is the relationship between the couple played by Silvina Cortés and Damien Fournier who, often surrounded by the ensemble as an intrusive hubbub of night world activity, find each other, have a one-night stand, go their separate ways, and, perhaps, find one another again.

There's a minimum of props – a flag, a few chairs – and music plays a key role. The bandoneon-led sound of tango is an easy delight anyway, and composer Szymon Brzóska’s interpretation of it via a five-piece musical group, stage right, is well-estimated, bursting with life where required but also dropping to loose downtempo arrangements suitable for the more interpretive modern dances. M¡longa is an eyeful, and holds the attention with vim, vitality and sheer hard-practiced skill.

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Overleaf: Watch trailer for Sidi Larbi Cherkaoui m¡longa

Flawlessly uniting atmosphere and melody is challenging. Especially so when creating music is approached unconventionally and with the desire to be individual. Having set her bar high, Juana Molina triumphs on all counts, again proving herself as a virtuoso artist who executes her vision with enviable assurance.

Latin America has learnt from harsh experience just what the legacy of dictatorship involves, when the structure itself may have been dismantled but the psychology that it engendered remains.

It's not so long since Daniel Barenboim sat around a table with Israeli officials telling him that Wagner couldn't be played in the homeland when someone's mobile fanfared the "Ride of the Valkyries", demolishing the opposition's case. At the opposite end of the scale to all that flash of battle-lust came last night's unexpected first encore to a Wagner second half – the Act Three Prelude to Die Meistersinger von Nürnberg.

"Helo, ti yw Mark?" A friendly-looking woman on the tiny plane asks me my name. She is a teacher from a Welsh-speaking school in Patagonia, Ysgol yr Hendre, escorting her pupils home from a trip to Cardiff. "I was told to look out for you on the plane. Come and sit with us!" she continues. I am heading to Trelew in the Chubut Province of Argentina to research ideas and gather texts for my BBC National Chorus of Wales commission, part of the 150th anniversary events marking Y Wladfa, the Welsh settlement in Patagonia.

The brackets around {150} are ambiguous, almost apologetic. The 150th anniversary of Y Wladfa (The Colony), the semi-legendary "oasis of Welshness" in the Patagonian wilderness has given occasion in Wales for the celebration of a most unlikely story. One hundred and fifty men, women and children left their homes all over Wales and created a new life for themselves, against all the odds, at the other end of the world. Sixty-six came from the villages around Aberdare and Mountain Ash in a valley 15 miles north of Cardiff.

A group of gunmen are roaming the Argentine rainforest jungle, terrorising local farmers in order to obtain the rights to their land. One farmer follows an ancient custom, praying to spirits to send a saviour. When a young stranger strolls bare-chested and barefoot out of the jungle, the farmer assumes his prayer has been answered.

In the past decade or so the Argentine director Lisandro Alonso’s minimalist masterworks have earned him an ardent, if particular following. With Jauja he’s moved beyond his comfort zone, by using professional actors for the first time and with more dialogue than in all his previous combined. The result is at once his most accessible film and his most mysterious, which is quite some trick. And it confirms his status as one of contemporary cinema’s great artists.

Six apocalyptic Argentine stories of revenge combine in this hugely enjoyable and extreme anthology. Producer Pedro Almodóvar must have been impressed by the perverse humour, and the lack of a handbrake as actions rocket out of control. Writer-director Damián Szifron is, though, the sole author of his characters’ nightmarish misfortunes.