London Philharmonic Orchestra & Chorus/Nezet-Seguin, Royal Festival Hall, London

Brahms's Ein Deutsches Requiem should be mandatory for anyone (and there are many) who has ever uttered a disparaging or ill-considered word against its composer. Under the conspicuously talented Yannick Nezet-Seguin, it shone, it thundered, it inspired all-enveloping awe and consolation.

But first there was the little matter of reconstructed Mendelssohn – and how quickly it evaporated from the memory. Marcello Bufalino's well-meaning but somewhat pointless completion of a third Mendelssohn piano concerto in E "for England" sounded oddly incomplete, as though that which was missing was still, well, missing. Strangest of all was the impression of piano and orchestra as two separate events – one or the other, question and/or response – meaning that little of interest united them beyond decorative cascades from the keyboard. The orchestral writing (almost entirely Bufalini's) was dowdy, quite without Mendelssohn's inner ear for fantasy. A dreamy cadenza in the finale brought forth a glimpse of that, but it came from nowhere and led nowhere. A bit of a stitch-up in quite the wrong sense: nice tunes, precious little interest beyond that. Roberto Prosseda played it prettily enough.

And then it was forgotten. As that richly consoling alliance between cellos and violas offered solace in lamentation from the opening bars of Brahms's requiem, and the chorus's words "Blessed are they that mourn" left one in no doubt as to its grateful recipients, Yannick Nezet-Seguin's labour of love on a work he clearly reveres put not a foot wrong. With sensitive, articulate singing from the London Philharmonic Choir, the fine balance between the work's deep compassion and its death-defying exultation was memorably achieved.

Awe was duly forthcoming as the mighty cortège of "Denn alles Fleisch, es ist wie Gras" rolled out, low horns and pounding timpani accentuating its black splendour, and those fugal codas were properly rollocking, hopeful affairs – blasts from the past powering towards the future. A requiem for the living, then, and at its heart, one soprano solo: Elizabeth Watts's prowess in Strauss served her well in this seraphic movement, the still, small, maternal voice of comfort for us all.