THIS evening on BBC2 television you may watch the second half of the opening concert of the 2017 BBC Proms from London's Royal Albert Hall. The programme consists of a single work, composed by John Adams, whose 70th birthday year this is. Harmonium will be performed by the BBC Symphony Orchestra and Chorus, and the BBC Proms Youth Choir, all under the baton of Edward Gardner. If the title of the piece sounds familiar, it may well be because it was the music chosen to mark the 50th anniversary of the Edinburgh Festival Chorus two years ago, and performed by them for the first of the new free public opening events introduced by Edinburgh International Festival director Fergus Linehan, combined with spectacular visual projections on to the outside of the Usher Hall.

The Festival performance of Harmonium was followed last year by Deep Time, which – to a soundtrack of the music of Glasgow band Mogwai – celebrated the Edinburgh Enlightenment, and particularly the work of geologist James Hutton, whose researches changed thinking about the age of our planet, with the visuals, again created by 59 Productions, using Edinburgh Castle, and the ancient volcanic plug on which it sits, as the canvas. By what is a most peculiar coincidence, the first substantial new commission of this year's Proms programme, from the pen of Sir Harrison Birtwistle, is a half-hour piece entitled Deep Time. You may hear Birtwistle's geologically-inspired work played by Daniel Barenboim and the Staatskapelle Berlin on BBC Radio3 on Sunday evening.

Perhaps it is more than a coincidence, and proof that imitation is indeed the sincerest form of flattery – a tribute from the Proms to the Festival in its 70th birthday year. In which case we can surely look forward to a future concert featuring something called Bloom, because that is the title of this year's opening event in Edinburgh, again sponsored by Standard Life in the second of what is a three-year support deal, and once again being created by 59 Productions, whose founding partner and creative director Leo Warner told me it was becoming the most challenging thing his company had done. Considering that their other canvases have included the Sydney Opera House, United Nations HQ, the Olympic Games, Broadway theatres and the Met in New York, that is something.

When the EIF programme was unveiled, Bloom had no shape at all, beyond being a 70th anniversary-marking event that took its cue from the 1947 ambition that the first Festival be a platform for the "flowering of the human spirit" in the dark post-war years. We know now how successful that aim to draw Europe back together through culture was to become, and we also now know more about what the Bloom event that celebrates that success will be like as well.

Unlike Harmonium and Deep Time, it will not be a one-off performance but an experience to be savoured in its own time over a two-hour period, from 10pm to midnight, and available over two nights, August 4 and 5. The music on this occasion is the work of Nick Powell, who is well known to Scottish theatre-goers for his work for the stage, and his fifteen minute composition – which does contain elements that fans of Mogwai may enjoy – will play on a loop while the installation is accessible. The site is St Andrew Square, presenting 59 Productions with ten different periods and styles of architecture to work with, innumerable tenants to talk to, and the towering Melville column at its centre, erected by lighthouse engineer Robert Stevenson to commemorate the Enlightenment's Henry Dundas. "Of all the things we have done," says Warner, "this is the most geographically particular. And putting people inside the experience is huge in a very different way."

"Putting people inside the experience" was exactly what made the festival important at its beginning. "Re-igniting an appetite for culture on an international level after the devastation of the Second World War," as Warner puts it. How worryingly relevant that goal seems once again, 70 years on.