And, her show-shopping number from Bernstein’s opera-operatta-musical, Candide, certainly provided an apt watchword for this concert performance at London’s Barbican Centre on Sunday evening, which fizzed and sparkled, oozing happiness and sweetness to wash away the occasional glints of darkness.

From the first downbeat of Kristjan Järvi’s baton, as he furiously kick-started a breakneck overture, to the stirring choral conclusion, the energy never once flagged, and the melodies kept flowing. Järvi control of Bernstein’s flexible structures, with their changing time signatures, flexible syncopations and cross rhythms was superb, and he deftly kept the large forces of the orchestra and chorus synchronised, give or take a few untidy ritenutos, dynamically driving them forward. It’s not often that one sees an entire viola section smiling beatifically to themselves, but that’s what happened here as they rang out yet another glorious overture melody, anticipating the optimistic sentiments of Candide’s and Cunegonde’s vision of future bliss, ‘Oh happy we’. The LSO’s instrumentalists obviously enjoyed the indulgent riches of this colourful and euphonious score, and relished the variety of the composer’s effortless pastiches and parodies, although at times I would have liked a little more brash boldness from the brass and reckless abandon from the percussionists!

The chorus were in boisterous mood, their carefree swaying and animated hand-waving, providing a dash or two of visual humour to match the primary-colour lighting which flagged up changes of mood, for anyone in doubt. Having collapsed anarchically as the Westphalian schloss Thunder-ten-Tronck succumbed to an enemy onslaught, the chorus gleefully bobbed and cheered — ‘Watch ‘em die! … Hang ‘em high’ — through the frenzied mayhem of the Auto-da-fé. Their rather uncoordinated involvement was funny the first time, but rather tiring on the second, third, fourth occasion. However, by the final chorus, ‘Make Our Garden Grow’, they were back firmly under the control of the conductor’s baton for the stunningly powerful a cappella declaration, ‘Let dreamers dream what world they please’.

Best of the soloists was Andrew Staples, as a wide-eyed, innocent Candide; he balanced a firm, focused tone with moments of more gentle reflection. The bright buoyancy of his opening ‘Life is happiness indeed’ had, without undue sentimentality, modulated by the end of his journey into a moving moment of realism and disillusion, as his love and hopes dissipated into ‘Nothing more than this’ — Cunegonde was really only in it for the money. Candide’s two Meditations in Act 1 were the highlight of the evening as, supported by piquantly alternating major/minor harmonies, he floated perfectly placed rising major sixths to convey his tender hopes that his teacher Pangloss’s maxim could indeed be true: ‘There is a sweetness in every woe’. Staples sincerity was utterly convincing as he put his faith in the ‘kindness’ and ‘sunlight I cannot see’; and strong harp and woodwind playing gave rhythmic and harmonic propulsion, suggesting optimism and resolution.

At times, Kiera Duffy might have done well to remember that power sometimes works best when balanced with restraint. For, while she dazzled in ‘Glitter and be gay’, crystal clear when striking the stratospheric heights of Cunegonde’s wild enthusiasm for a bling-laden life of recklessness and glamour, she allowed her enthusiasm to get the better of her and at times was in danger of slipping into melodrama and histrionics.

She was matched in her excesses by Kim Criswell, an old stager of musical theatre and ‘cross-over’, whose Old Lady was a wild, backcomb-haired banshee, exuberantly flinging herself — and her partners — into the tempestuous tango of the aptly titled ‘I am easily assimilated’, and the musical hall antics of ‘What’s the use’. Marcus DeLoach, as Maximilian, was one of the few whose diction was unfailingly crisp and biting; and, in various supporting roles, Jeffrey Tucker, Matthew Morris, Charles Edward, Jason Switzer, Peter Tantsits and Michael Scarcelle were uniformly accomplished.

But, I found Welsh baritone Jeremy Huw Williams a disappointing Pangloss; he distinctly lacked the warm openness of sound needed to convey Pangloss’s spirit of innocent optimism. There was little sparkle, despite his diamante-studded tie, and he fell back on bluster and posturing. Both pitch and words were pretty indiscriminate, which made the title of his aria, in his second role as Martin, wryly ironic — ‘Words, words, words’.

Certainly, there is nothing sacred about Bernstein’s text. No fewer than six contributors had a hand in the book and lyrics, and it underwent numerous revisions, with Bernstein himself being involved in at least seven of them! Here we were treated to a cynical, occasionally acidic, narration by Rory Kinnear — updating that prepared by Bernstein and John Wells for concert performance. Kinnear reprised some of the bitter scepticism of his recent Hamlet at the National Theatre. Leaping blithely onto the platform, he was a master of droll scepticism, eye-brows arched, tongue firmly in-cheek. I suspect that many of the topical witticisms were added, or even improvised, by Kinnear himself; his voice amplified, we could sharply hear every riposte, something which could not always be said for the singers themselves who suffered when Järvi gave chorus and orchestra free rein, despite their placing at the front of the stage. It didn’t help that, although the libretto was printed in the programme, it was impossible to read the text in the darkened auditorium — at least during in the first Act before, presumably, complaints made their way to the stage management …

There was one ‘wrong note’ in Kinear’s narration, however, and it came right at the end when, interrupting the triumphant final cadences of the gloriously overwhelming chorus, he sardonically asked the audience, ‘Any questions?’, a quip which jarred with the musical sentiments expressed. Of course, there are no ‘questions’: the music is unambiguously jubilant, the ‘message’ clear.

That said, this flippant parting shot couldn’t dampen my spirits at the end of this wonderful performance and, despite the torrential June downpour, my smile lasted all the way home.

Claire Seymour