What is it they say about Sir John Eliot Gardiner? That he drives music too hard and squeezes the character out of it? Then I give you Exhibit A: this delightful performance of La Damnation de Faust, by turn relaxed and hair-raising. Like a musical wicked uncle, our senior Berlioz conductor (since Sir Colin Davis died, at least) teased the whimsy from this great score as surely as the horror.

JEG gathered an unbeatable team to give this ‘dramatic legend’ its BBC Proms outing. Such was the commitment and fervour of all concerned that it was easy to overlook the work’s structural mess, with melodic episodes like the Hungarian March and the Easter Hymn shoe-horned in for the hell of it. Indeed, little of dramatic import occurs at all in the first half-hour, although the dividend in sumptuous music is worth a devil’s ransom. And with Michael Spyres on hand to agonise in noble fashion even the early stuff seemed vitally important.

The tenor was at his very best in a role he sings regularly, and his set pieces had a deliciously wrong-footing quality as Faust's dark thoughts were refracted through vocal sunlight. The great soliloquy “Sans regrets”, replete with ennui and douleurs and poison, was irresistible; “Merci, doux crépuscule”, the aria he sings when he's alone in Marguerite’s room, was riskily euphoric and, at the line “Que j’aime ce silence”, quite literally light-headed.

Spyres played the straight man to Laurent Naouri’s ultra-mischievous Méphistophélès. The urbane French baritone, who was at his silkiest, sidled onstage through the brass section to snarky asides from the trombones and proceeded to subvert concert protocol by going for walks, singing half-reclined on his chair and throwing pregnant glances hither and yon. It was all scrupulously rehearsed, of course, and it brought both the character and the concert vividly to life.

While there was little by way of visual staging, aurally it was pure theatre, with a feast of textural variety and some memorable offstage contributions from the young men of the National Youth Choir of Scotland. Indeed, one of the performance’s great strengths was its juxtaposition of the Monteverdi Choir’s mature mixed voices and this polished but youthful ensemble. For most of the time all the choristers joined together; but when they sang separately, for example as soldiers and students, the tonal contrasts between them were extraordinary. The excellent Trinity Boys Choir added a third layer to the timbre in the final sections but was sadly underused.

Ann Hallenberg sang Marguerite with a timbre of spun sugar and a voice of pure silver. Her famous ballad, Le Roi de Thulé, was accompanied by some ethereally ravishing viola playing from the Orchestre Révolutionnaire et Romantique and would have been an indelible episode had her diction been more secure. As it was, the Swedish mezzo sang like a dream whose meaning (from where I was sitting, at least) was a mystery.

The ORR played with its usual panache, although it was hard not to muse on whether Berlioz wouldn’t rather have heard his music on the latest instruments rather than the oldest ones. Musically he was way ahead of his time, not least in his orchestrations for this forward-looking work from 1846, the year of Mendelssohn’s Elijah. No matter; they were impeccably played.

On a narrative level La Damnation de Faust, like several of Berlioz’s large-scale works, is neither fish nor fowl, so there is little to be gained by seeking to find fault with its structural loopiness. On its own terms it’s an entertainment matched by few other dramatic oratorios, an unapologetic treat and a composition of immediate appeal – especially in a performance as affectionate and affecting as this. The fun was a bonus, and all plaudits to Gardiner for embracing it. When no less a figure than Ashley Riches stepped out of the choral ranks to sing the beer-sloshing role of Brander, it made a heady night all the more intoxicating.