Verdi Requiem, Mariinsky Orchestra and Chorus, Gergiev, Barbican Hall

After conducting two performances of Parsifal since Saturday and one of Mahler’s Eighth Symphony, most human beings would be spending a day curled up at home. But Valery Gergiev doesn’t know what carpet slippers look like. Besides, he’s currently on tour in Britain with his Mariinsky Opera forces, and he’s conducting nothing but blockbusters. Last night, Verdi’s Requiem in London. On Good Friday, it’s the epic Parsifal again, in Birmingham.

Brisk rhythms melted into a flow of milk and honey

No wonder he looks so ashen. Yet the weariness is only on the outside. For, armed with his fluttering fingers, Gergiev took charge at the Barbican of a zinging Verdi performance, fierily dramatic, achingly lyrical. True, this opera in ecclesiastical dress – Hans von Bülow’s old description won’t go away – needed a little more choir power to unleash the full force of Verdi’s great national monument, composed as a giant laurel wreath for the poet and novelist Alessandro Manzoni. Even 54 stout Russian voices weren’t sufficient to sail over the orchestra every time, or clarify the fugal writing in Verdi’s joyous Sanctus, a setting interestingly despatched by Gergiev, with its brisk rhythms melted into a flow of milk and honey. But there were definitely good artistic reasons for launching the Introit in such an awestruck, slow whisper, the words just on the edge of audibility: all part of Gergiev’s plan to underline the volcanic eruptions of timpani, trumpets and the waking dead, imminent in the Dies Irae.

Some of the soloists, all new faces on this Mariinsky tour, also worked their best magic when the decibel level was reduced. Whenever that soft-grained bass-baritone Ildar Abdrazakov muted his tone, it was easy to feel the shiver of death and the world’s sorrows cradled in his hands; less so when the voice opened up. Viktoria Yastrebova, as wan and plaintive in demeanour as the grief-stricken maidens in Edward Gorey’s drawings, also achieved her best effects switched to the quiet mode. High in the air in the Agnus Dei, her pearly soprano stayed beautifully focused and touched the heart. Once volume increased, as in the core of her Libere me, control at some points wavered: odd notes were scooped and smudged; beauty became compromised.

You could always explain tenor Sergey Semishkur’s peevish passages as the result of a pair of tight shoes

The critic’s microscope, if ruthlessly applied, could discover other flaws, too. But the happy truth is that, unlike Andrea Bocelli’s infamous crooning in Gergiev’s CD version issued in 2001, none of them mattered in the long run. Olga Borodina’s expressive, multicoloured mezzo soon woke up to reign in glory; and you could always explain tenor Sergey Semishkur’s peevish passages as the result of a pair of tight shoes. For this Verdi Requiem, above all, was a group endeavour, with voices and orchestra sinking in prayer or rising in terror in perfect accord; decorated along the way by clean and fluent instrumental playing from musicians who know their conductor backwards, sideways, upside down. Woodwinds were the stars of the show: consistently graceful, daisy-fresh, though they couldn’t have felt it by Wednesday night.

This was also a supremely organic performance: compact, moving with inexorable momentum from section to section with the theatrical and the spiritual keenly balanced. What if Verdi treats his soloists at times like opera stars in greasepaint? It’s the music’s humanity that matters most, and Gergiev’s touring forces delivered that in spades. Can they rest up today, at least?