The Barbican has built a steady reputation for almost unclassifiable large-scale art exhibitions, particularly in architecture, design and photography: they have been underestimated pioneers, often working in areas themselves under-scrutinised. Thus they often manage to surprise, and so it is here.

Marc Rees (b 1966) is an interdisciplinary artist-performer from Wales whose works are renowned for imaginitively mixing media, as well as for their underlying sense of fun. Over the years he has been based in Berlin, Amsterdam and Canada, and now runs the collaborative arts company RIPE (Rees International Project Enterprizes).

Kaite O’Reilly’s new play is a dark dark comedy, a Chekhovian family saga on a mainly bare stage that handles its subjects of aging, death and family with a rich and grounded intellectualism to be expected of the playwright’s work. The production itself skips lightly along the thin line that separates reality from a discomfiting dreamscape, the waiting room: everyone is waiting, for death, for life, for family members to arrive. It is an ominous comedy.

David Jones’ black and white drypoint – a drawing made by incising lines on a copper plate with a diamond-tipped needle and then printing from the plate – is a view of the nativity which is fresh, full of wonder and a highly intelligent naïveté. It shows all the sophistication of an artist who has looked at the art of the past but is also fully aware of modernism’s confusions of perspective, able to deploy them even when depicting recognisable scenes.

While Christmas is the season when traditional theatres trot out the tired clichés of panto, the ever-innovative National Theatre Wales have decided, in their wisdom, to stage a surreal, psychedelic theatre-gig at the Sophia Gardens cricket ground in Cardiff.

Switching between the orderly and the chaotic, David Jones’ depiction of Noah’s family building the ark immerses us in the drama of the moment while simultaneously holding us at some point out of time, to emphasise the story’s ancient roots.

"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 city of Brecon (county town of former Brecknockshire, now lost in the spurious and far-flung county of Powys) is a long way from Leipzig and on the face of it has little in common with the home of Bach and the native city of Wagner. But once a year for the past decade this rainy, hill-girt metropolis on the upper reaches of the River Usk has played host to a festival of Baroque music, and particularly Bach, that would match pretty well anything likely to be offered in the Thomaskirche.

Iliad is the third collaboration between National Theatre Wales and “the two Mikes”, directorial duo Pearson and Brookes. The pair have been responsible for two previous highlights of the still young company’s back catalogue, The Persians (2010) and Coriolan/us (2012). Aeschylus was re-imagined on a Brecon Beacons military range and Shakespeare recast in an RAF aircraft hangar, so it is perhaps surprising that the ultimate epic drama of war is staged in an actual theatre, the compact and modern Ffwrnes in Llanelli.

Jason Hughes belongs to an influential generation of actors who emerged from South Wales in the 1990s. A promising rugby player as a teenager, his head was turned by theatre. Ruth Jones and Rob Brydon were only a few years above him at school in Porthcawl. In the National Youth Theatre of Wales he met Michael Sheen. The name may be less familiar, but the face is known from two very different Joneses whom Hughes has created on television: Warren Jones, the young gay lawyer in This Life, and Ben Jones, John Nettles’s sidekick in Midsomer Murders.