They used to nickname Mahler’s Seventh Symphony “The Song of the Night”, and it is easy to understand why.

Its five movements are crammed with nocturnal hallucinations, visions of Dureresque medievalism, whether of military night-watches or triumphant banner-waving festivities, and it needs a firm hand to guide us through all its byways.

And Valery Gergiev achieved this triumphantly on Friday, cajoling and manipulating a splendid London Symphony Orchestra in an enthralling delivery of this tricky score.

Probably at the time of its composition Mahler himself was the only conductor who could tame this monster. Since then Bernstein, Rattle and now Gergiev have unlocked the key to its success.

Gergiev’s approach was to allow events to unfold in a linear fashion, while at the same time making sure the little organic cells which make up the texture, recurring time and again, registered in the listeners’ memory.

There were scarcely any breaks between the movements, almost as though Gergiev were determined to underline a seamless unity in the music – and it certainly worked.

Despite its vast orchestral demands, this is a chamber music-textured composition, and its demanding solo contributions were beautifully delivered, not least by the violin and viola principals.

Balances were instinctively judged, as were tempi. Gergiev wrought magic here.

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