The onstage mingling of orchestra, soloists, and conductor prior to this seasonal performance of Berlioz' L'enfance du Christ was presumably designed to lend a more intimate, informal tone to the start of the evening so that the music could "emerge", as it were, without the usual formalities of bows and applause.
And it might not have looked so puzzling and stage-managed had the performance not started a quarter of an hour late. Whatever the reasons for that, it was, though, well worth the wait.
You could read from the close attention and tiny gradations of colour given to the bare opening wind chords that the work's inspired less-is-more chamber quality was something that Mark Elder found both challenging and inspiring. Berlioz, master of the big effect, dazzles us again and again here with his subtlety and refinement: the colouristic effects are still audacious but they are born of masterful restraint so that a single fortissimo string chord or tremolando can achieve disproportionate dramatic impact or conversely a sustained note in the horns so quiet that it's like hearing (just) an overtone can lend such mystery - like gazing at a series of ancient illuminated frescoes.
That's the impression that this quietly inspiring masterwork gives us and hearing it unfolded here with such awareness and care for detail was gripping in ways that I cannot recall having felt before. The progress of that ever changing little "Nocturnal March" near the start reflected the infinitesimal shifts in accent and dynamics that Elder asked for and got from the Britten Sinfonia - likewise from the newly formed professional chorus, Britten Sinfonia Voices, whose balance and blend and sensitivity on and off stage reflected how satisfying this music must be to sing, not least, of course, the perennially enduring "Shepherds' Farewell" with its quirky rustic pipes.
But what finally achieved true ascendancy for the performance was the solo singing. Throughout the evening Sarah Connolly and Roderick Williams as the holy couple radiated the sheer pleasure of singing such grateful music, their voices tracing its contours as one. Neal Davies plumbed the darkest recesses of his bottom register as the tormented Herod only to find a powerful benevolence in the Ishmaelite's music (what a telling "double" that is). As for Allan Clayton - what a special singer he is evolving into. The narrator's final number with chorus brought from him an inspirational fervour, head-voice opening gloriously to the final message of redemption through love.