One of the stranger aspects of the last twenty years of operatic history is that one of the most provocative of all productions was not of an opera at all. In his Theodora for Glyndebourne in 1996, Peter Sellars set Handel’s quiet reflection on virtue, martyrdom, and execution in the modern United States. His staging ended with Handel’s heroes – a Christian leader, Theodora, and her Roman lover, Didymus – strapped to gurneys in a Texan military institution, singing the serene final duet that welcomes the oncoming angels as a lethal drug cocktail slowly entered their bodies. It’s shocking to watch even now, one of the greatest examples of theatre that challenges. Yet Theodora isn’t an opera, but an oratorio.

Theodora was neglected in Handel’s own lifetime, and continued to be until around the time of the Glyndebourne production. Sellars’ staging revived interest, though, and it now receives relatively frequent performances, especially in its original form on the concert hall stage. Many of the leading period-instrument conductors have recorded the work, although few modern-instrument groups have dared try. And there can be no doubt that the subject matter brought out the subtle best of Handel. The Christians have contrapuntal writing comparable to that found in Bach’s Passions, while the three main characters all receive a series of uncommonly profound, often brilliant arias, songs of dignity, chaste passion, and a total faith alien to modern audiences.

This Carnegie Hall matinee – prefacing the Super Bowl, of all things – concluded a US tour for The English Concert and Harry Bicket. If it did not match the sheer emotionality of that Glyndebourne event, it could hardly be expected to. At least one might have expected rather more consistent playing from Bicket’s orchestra, one of the foremost “historically-informed” bands. Just four first violins made for a tinny, recessed sound in a hall as large as this, while balances generally tended, unfortunately, to emphasise (all too numerous) wrong notes at precisely the wrong moments. Bicket focused on picking out brutal details rather than generating a flowing articulation, or the long lines that many of Handel’s arias require, and seemed determined to impose effects whenever possible. That said, his pacing was inerrant, especially in transitions between arias and recitative.

Such pacing allowed an impressive cast to shine. David Daniels was Didymus in the Sellars staging, and if his voice now takes longer to warm up it has mellowed nicely. His virtuoso elaborations were too showy for my tastes – although that is largely the point, of course – but in the quieter moments he found a radiant depth rare among countertenors. His Theodora here was Dorothea Röschmann, quite a different artist with a more Mozartean than Handelian voice. Her English was unconvincing at times, but she amply possessed the aura of one not meant for this world. “Angels ever bright and fair”, Theodora’s aria with string quartet, was poignant in its simplicity, even if “Lost in anguish” felt rather melodramatic. These are not two voices that would be expected to blend well, but they somehow managed to in the crucial duets, two of Handel’s greatest, that bring the second and third acts towards their close.

Sarah Connolly had perhaps the toughest task of all, at least for anybody who is familiar Lorraine Hunt Lieberson’s work as Irene. Irene is the Christian leader, devout but concerned for the fate of Theodora and the convert Didymus, and for her Handel reserves the most arresting arias, including “As with rosy steps the morn” and “Bane of virtue, nurse of passions”. Connolly was faultless, fulsome in tone and dignified in manner, although her finest moment, “Defend her Heaven”, was the victim of premature applause. Neal Davies sang with gusto as the governor, Valens, with a particularly vicious curtness to his lines. Kurt Streit, sadly, struggled as Didymus’ faithful friend, Septimius. Special mention, though, ought to be reserved for the Choir of Trinity Wall Street, a choir of outstanding clarity and versatility that imbued its all too scarce appearances with meaning at every turn.