Louis MacNeice was – in his own words – “in a state” when he wrote The Dark Tower. It was the autumn of 1945 and the poet had been through the war and seen his share of horrors. Despite being a non-combatant, he had experienced and reported on the blitz, cutting his BBC radio teeth on dramatised features with a “London can take it” theme. He’d lost friends, in particular his school friend Graham Shepard (son of illustrator EH). Graham’s death, in the battle of the Atlantic, had a profound effect on him.

What was it all for, the suffering and death? And why was MacNeice a living (and, he suspected, rather useless) poet, rather than a drowned (and therefore heroic) sailor, like poor Graham? These questions are at the heart of his radio play The Dark Tower. Inspired by Robert Browning’s poem Childe Roland to the Dark Tower Came, it’s a parable on the timeless theme of the quest, and it became a landmark in radio drama.

MacNeice was a relative newcomer to BBC radio drama, and ready to innovate. In a moment of inspiration, he decided that the soundworld of his play would dispense with the usual “spot effects” – coconuts for horse hooves or the clink of teacup and saucer by the microphone. Instead, the work’s mythical setting was to be evoked purely by music. And MacNeice’s BBC boss, Laurence Gilliam, recognising the quality of the script which had landed on his desk, sent it to the composer who would do it justice: Benjamin Britten.

Britten and MacNeice knew each other well and had friends in common. One of the most significant was the beautiful “flame-haired” singer Hedli Anderson. Hedli was a member of the experimental Group Theatre in London, for which both MacNeice and Britten had written in the 30s. In 1942, thrown into each other’s arms in wartime London, MacNeice and Anderson had a Soho wedding, passing the hat among the guests to whip up 25 bob for the registrar. And Hedli, an actor as well as singer, landed a part in a subsequent production of The Dark Tower. MacNeice’s love life was often a bumpy one: seven years before, his first wife had abruptly left him for another man, leaving MacNeice to cope with their infant son Daniel.

WH Auden was another link. He and MacNeice, rival poets, nevertheless knew and liked each other. They took a trip to Iceland together in 1936. Pony trekking around the ice fields, and sharing a sodden, all-too-collapsible tent, they discovered a delight in each other’s conversation. They collaborated on a larky account of their travels, which became Letters from Iceland.

Britten had spent much time in the 30s collaborating with Auden, and getting the benefit of his advice on matters both artistic and sexual. Britten had worked with Auden for the GPO Film Unit, most famously providing the accompaniment for Auden’s poetry in The Night Mail. As a very young man, stopwatch in one hand and pencil in the other, Britten learned to scribble down ideas which would work to precise timings, to underscore the drama of the images, and help to tell the story. Crucially, he was able to write creatively for scenes and stories. He was scornful of the crude and episodic music of many silent films, but later described how useful a discipline writing film music had been: “I had to work quickly, to force myself to write when I didn’t want to … It was also extremely good practice for me as a young composer to take exact instructions from the directors and producers and to try to please them.”

But Britten would not be taking exact instructions from anyone for very long. By 1945, his meteoric rise to fame was under way: in the same year that MacNeice wrote The Dark Tower, the composer had completed Peter Grimes. In the same month that he answered the call of MacNeice’s boss, he also composed A Young Person’s Guide to the Orchestra, now one of his most popular works (culminating with, as David Hemmings so memorably described it, “The champagne moment! F***ing great!”)

The first broadcast of the play, in January 1946, generated mixed reactions. MacNeice’s neighbour Goronwy Rees told him it was “bloody awful”, and a drunken scuffle ensued, during which MacNeice was knocked down the stairs. But friend and poet Henry Reed found it inspiring: “I am sure yours is the way radio must go if it is to be worth listening to; I have always thought your claims for its potentialities to be excessive; I now begin, reluctantly, to think you may be right, and am very glad.” And, as good as his word, Reed himself went on to a have a successful career in radio drama.

So tonight, when we gather under the tower of St Bartholomew’s church, Orford, to perform The Dark Tower with 16 players from the BBC Concert Orchestra, conductor Robert Ziegler and 12 actors, we have several things to celebrate and live up to.

One is radio drama itself, which was a youthful art when MacNeice took to it, but which – despite all expectations to the contrary – is still going strong. Soon after the broadcast of The Dark Tower, the BBC’s Third Programme was launched, and MacNeice immediately began to write for the new station. It has now transmogrified into Radio 3, that heady mix of classical/jazz/world music/arts – and drama.

Another thing to celebrate is Britten’s music, some of which – like Curlew River – was premiered in this same church. When he wrote the music for The Dark Tower, he was only 31 years old. When MacNeice delivered the manuscript, he asked that the music be done “with the greatest economy”, to create the right atmosphere. He wanted the trumpet’s challenge call to make the listener’s “hair stand up”, and the music for the forest scene to suggest “shivering twigs and murmuring shadows”. How far Britten succeeded in this you may judge for yourself.

But we will also be celebrating one of the most remarkable collaborations in the history of the genre. To hear MacNeice’s verse and Britten’s music working together on the imagination of the listener is a unique opportunity. Under the tower of Orford church, and in sight of the weird disused-military-bunker constructions of Orford Ness and the medieval keep of Orford Castle, we will be able to close our eyes, and listen as MacNeice and Britten build their Dark Tower.

• The Dark Tower is at St Bartholomew’s church, Orford, Suffolk, on 27 and 28 October and will be broadcast on Radio 3 on 29 October and available on iPlayer for 30 days afterwards.