HANDEL’s 1750 oratorio Theodora had a slow start, and was cancelled after only three Covent Garden performances. Fortunately, tastes change, and recently both performers and record companies have taken it to their hearts, as did the Barbican audience.

In Antioch, the Christian princess Theodora is incarcerated in a brothel for her refusal to sacrifice to Jove, only to be rescued by her lover, Didymus, before both are martyred for their faith. This gloomy tale, Handel’s favourite among his oratorios, brings forth some of his loveliest music, to which the period-instrument orchestra Arcangelo did full justice.

From the overture, crisp, rhymical, beautifully articulated, we knew that we were in safe hands. Jonathan Cohen, directing from the harpsichord, chose to highlight the work’s musical rather than dramatic aspects, and he had a way of slowing the beginning of an aria, emphasising a word or lingering on a cadence that bejewelled the performance with innumerable lovely moments.

The choir produced a chamber sound that belied their size, and sang with astonishing clarity, even if their contributions were rather staid on occasion. They made little distinction between the Christians’ sober piety and the pagans’ cheery gloating, even when this was reinforced by a pair of raucous natural horns. Their standout moment was Handel’s own favourite chorus, “He saw the lovely youth”, depicting the raising of the widow’s son in Luke, their opening slow chromatic figures sombre, brightening into joy as the youth is restored to his mother.

Among the supporting cast, Anna Stéphany was a grave Irene, her recitatives beautiful music rather than dramatic contributions. She came into her own in her arias, colouring “As with rosy steps the dawn” with sweet conviction. Adam Plachetka’s dark bass-baritone lent real menace to the blustering Valens.

Louise Alder sang Theodora with inner rapture, her very pure, silvery voice a perfect contrast to the more honeyed tones of the countertenor Tim Mead’s Didymus. Their duets had a particular quality of faith mixed with earthly longing, never more evident than when the quiet joy of Didymus’s solo “Streams of pleasure ever flowing” led without a pause into to their closing “Thither let our hearts aspire”, a gentle, ecstatic looking forward to the life to come.

The choir’s soft “O love divine” was a moving ending, greeted by the audience with a moment of absolute silence. A recording of the work has just been made, which is extremely good news.