Many listeners – even or especially those who had been beguiled by The Midsummer Marriage – could once take refuge in the harsh assessment of Tippett’s biographer, Ian Kemp, that King Priam was “the most didactic and theoretical of his works”. This Kent Opera production proved them wrong. The Royal Opera premiere in Coventry had been overshadowed by the acclaim for Britten’s War Requiem, first heard the following night, and the big voices and grand, clangorous manner of the fine Decca recording (based on a later Covent Garden production) are fully operatic in scale and projection.

By contrast, Roger Norrington and the young Nicholas Hytner push right into the claustrophobic citadel of the drama to find out, in the composer’s words, “what happens when the psychological balance symbolised by marriage is knocked awry by responsibilities, war and fate”. Acoustic, camera and microphones are close, oppressively and rightly so. We are but a few feet from Rodney Macann’s piercing blue eyes as his Priam rebels against the choices that Tippett so relentlessly adumbrates: to smother Paris or love him, to sacrifice Helen or Troy, to confront Achilles or retain his royal dignity – how different from the hopeless determinism of Britten and Owen, where men are “the foolish toys of time”, to quote Eric Crozier for St Nicolas.

Robin Lough’s direction for TV uses the tricks of the medium sparingly, and to most telling effect in the blood-lust of the Trojans’ vengeance trio at the end of Act 2, answered by Achilles’ war-cry with Verdian immediacy. All the principals have the measure of their roles. If Sarah Walker’s Andromache, Neil Jenkins’s Achilles and Macann’s Priam do most to stop us in our tracks, perhaps it is their painfully human heroism that Tippett was most interested in himself. In the brief but demanding role of the boy Paris, Nani Antwi-Nyanin also deserves a special mention: Tippett was not in the habit of writing down for younger performers.

Kent Opera sank in 1989, no longer kept afloat by government subsidy. There could be no more imposing memorial to the power of its work, and to the determination of its artistic director, Norman Platt, who died in 2004.