What is there to say about Hector Berlioz’s Roméo et Juliette? A “dramatic symphony” in seven movements, featuring small and large choruses, and three soloists (two of whom sing for around five minutes each and one who sings for around 30), as well as a treasure trove of unusual instrumental combinations and sounds, it is safe to say this is something of an odd bird. Add to this a libretto by Émile Deschamps which not only misses out a great deal of Shakespeare’s drama but goes so far as to reorder it and even mentions the playwright by name, and it becomes apparent there’s something truly wacky afoot. And even that’s leaving out Berlioz’s frankly astonishing approach to melody and harmony. With echoes of Wagner, Brahms, and even Debussy scattered throughout, as well as a mind-bending reimagination of the Baroque “mad scene” for a new age, it is difficult to believe this piece was written in 1839.

Though Berlioz explicitly denied such, Roméo et Juliette is more concert-opera than symphony, and it was in this vein that Valery Gergiev and the London Symphony Orchestra performed, alongside soloists Olga Borodina, Kenneth Tarver and Evgeny Nikitin, standing in at short notice for Ildar Abdrazakov; singers from the Guildhall School formed the small, narrating choir and the London Symphony Chorus the large, characterful menagerie of Montagues and Capulets.

After a strong start, it seemed the performance’s energy began to flag in the great love scene and throughout the next two movements. This may be to do with Berlioz’s music – played without an interval, this is a colossal work, longer even than the Requiem, and containing ideas that can only really work with a full operatic staging; the fifth-movement mourners’ chorus “Jetez les fleurs” cries out for costume, motion, and gesture of the kind a static symphony chorus cannot, by definition, provide. However, where slower music could occasionally lack verve, the brash, Verdian showpieces stood out, and a star turn from Nikitin transformed the concert from merely very good to outstanding.

Gergiev’s reading was truly operatic; untroubled by excessive interpretation, he largely allowed a fantastic orchestra and strong soloists to get on with things. On the other hand, in the places where a little conductor-led nuance is required, the performance lost a little vigour; this was noticeable particularly in the rubato-laden love scene, where the violins never found as ravishingly beautiful a tone as is required, and some ensemble issues between cellos and horns meant Berlioz’s long melodies occasionally lacked expression. Moreover, although Berlioz’s delicate counterpoint is fascinating, I found myself wishing for a little more differentiation between melody and accompaniment; when both assume equal importance, the effect is overwrought – static and languishing rather than fervent or passionate. Queen Mab’s scherzo lacked delicacy, strings never matching the winds’ staccato bounce, creating rather too homogenous a sound. It was only with the horns’ entry towards the movement’s end that the performance found the requisite scamper, coming to an elfin, quicksilver conclusion.

Such a drop in standards proved the exception rather than the rule for the LSO, as the rest of the symphony demonstrated. From a vehement but lively fugato opening, it was obvious Gergiev would savour absolutely the character of one of Berlioz’s most ambiguous works. The trombones and brass were in brilliantly crass form, and yet were also capable of exquisite dramatization, as the former’s recitative near the opening proved, evoking perfectly the imperious voice of the Prince. Principal clarinet Andrew Marriner’s ghostly echo tones were well-matched by Gergiev’s furious account of the mad scene in the sixth movement, and Fabien Thouand’s second-movement oboe solo was pure bliss. I must also mention the 12 singers from the Guildhall School, whose attentiveness and care for the colour of their sound in the earlier narrative interjections gave their singing a brilliant drama, outshining even the full forces of the London Symphony Chorus.

Though Borodina and Tarver sang with exquisite beauty and heaps of charisma respectively, their brief roles hardly allowed them any particular presence in the greater dramatic fabric. It was Evgeny Nikitin who, despite being a substitute, absolutely stole the show in his role as Friar Laurence. Singing with total, implacable authority, this was no bumbling Laurence as we know him in Prokofiev’s ballet, but a voice of reason, Nikitin with absolute control over his whole range. His vocal strength energised the whole ensemble, the massed choruses all coming together for a sublime conclusion after an ideally waspish, spiky vocal account of the opening fugato, the families’ differences resolved through the stern words of the Friar. If I wasn’t as impressed as I had been in the last of Gergiev’s Berlioz concerts I reviewed, I left in little doubt that Gergiev and his orchestra are as fine a team of representatives as Berlioz could want.