2020 vision: Lily Allen returns from obscurity to light up the longest-running music show in television history

I know, I know, you've hardly woken up after the King's Speech and you're still recovering from the Doctor Who Christmas Special (Florence Welch – the best doctor ever). But let's do a bit of time-travelling of our own, back across the past decade in the arts, way back to Copenhagen at the end of 2009. Remember the climate-change conference? If it yielded little else, at least it gave us David Hare's The Green Machine. His one-man, real-time, tour-de-force staging of the final 36 hours of the conference, playing 14 heads of state (with his quiff as his only prop), was performed once only, thank God, and has gone down in theatrical legend. Were you one of the seven people said to have stayed awake until the word-for-word recreation of the 4.30am treaty ratification? Bravo!

The relationship between film and art, which had begun in the Noughties as a bit of a fling, developed into a full-blown affair. The culmination was that unlikely Sunday in March 2014 when Martin Creed's Paula Radcliffe documentary, 26.2 – about the tragic runner's final, catastrophic tilt at the Olympic marathon title in London two years previously – took Best Documentary at the Baftas. Within minutes of Creed's acceptance speech, of course, Shane Meadows was at the podium, picking up Best Screenplay for 24 Hour Arty People, his satire of the YBAs, followed by Tilda Swinton, who richly deserved her Best Supporting Actress Oscar for her turn as Charles Saatchi. (Come on, Tilda, five years behind the pumps at the Queen Vic will do – let's see you back on film, please.)

How to explain the astonishing global broadcasting success of The Valley? It's easy to forget that BBC was so vexed by the demise five years ago of its licence fee ("li-cence feeee" – there's a phrase you haven't heard for a while). But ever since BBC Television went subscription-only, ditched its website and ploughed those hundreds of millions of pounds into original drama, it hasn't looked back. Nevertheless, after the Noughties, in which we lapped up the uber- American series such as The Sopranos and The Wire, who would have thought that America and the rest of the world would today be going wild for season five of The Valley and the vicious turf wars of Welsh hill farming? All together now: "The last Englishman who tried to diddle me on my sheep dip is still getting used to his wooden legs..."

Not every high-stakes gamble paid off over the past 10 years. The nation still mourns the tragedy that was Matthew Bourne's staging of The Rite of Spring in 2013. The story is horribly familiar: Bourne had planned to celebrate the centenary of Diaghilev and Stravinsky's collaboration with a cast made up solely of centenarian dancers: stress, the punishing choreography and, according to the coroner, plain old age led to the death of eight of them shortly after the press-night performance. It was, wrote our own critic Jenny Gilbert, like "Exit: the Musical". Bourne will be eligible for parole in 2024.

And thank you, thank you, thank you, Anna Netrebko. The diva's on-off affair with Prince Harry has been the opera that keeps on giving over the past eight years. No less fun, if more edifying, has been Gareth Malone's tenure running the English National Opera for the past four years: spring 2020's highlights include a revival of his risqué Edenbridge Venture Scouts production of Death in Venice.

And who could have predicted Lily Allen's resurrection from the where are they now file? Five years at a cult – sorry, alternative community – in Thailand, and then up she pops on Jools' 2018 Hootenanny, seven months' pregnant with child number five (we think), tatooed from neck to toe and playing a very mean saw sam sai fiddle. Scary.

But not as scary as the most contentious artistic decisions of recent times: the axing of The Archers from Radio 4. The public disturbances in Winchester, Richmond and Solihull in November were bad enough; but the ongoing hostage situation at Broadcasting House, undertaken by the self-styled Ambridge Martyrs' Brigade, enters day 27 at the time of writing, with no sign of a peaceful conclusion. The hostage-takers are demanding the instant recommissioning of the radio soap opera by 1 January 2020, otherwise they claim they'll "start releasing the offending controller Mark Damazer piece by piece". A finger, thought to be Mr Damazer's, was removed, along with a recipe suggestion, from an Abel and Cole box thrown from the fourth floor last Thursday.