There are some musical compositions that have always been a bit of a gamble, for composers, performers and even listeners. They might be exceptionally difficult, require extraordinary forces, or show such originality as to be perpetually startling. Monteverdi’s dramatic madrigal Il combattimento di Tancredi e Clorinda meets all three of these criteria, and perhaps it was the inclusion of this bizarre, remarkable work in the Academy of Ancient Music’s Dawn of the Cantata programme which made the concert such an exciting prospect to such a huge number of listeners – a sold-out Wigmore Hall and thousands of home listeners courtesy of BBC Radio 3’s live broadcast – not to mention the dozen or so performers involved.

Doubtless, though, this excitement was due in a large part to these performers themselves. The Academy of Ancient Music is a period-instrument band that radiates pure enjoyment in its music-making: as unfussy, unpretentious and devoid-of-cobwebs a bunch of historical performance buffs as is likely to be found anywhere in the world. This essential spirit was communicated directly upon their entrance; hardly had their chairs been filled that we were launched into the joyous polyphony of Falconieri’s Ciaccona in G major, featuring a brilliant dialogue between virtuosic violinists Pavlo Beznosiuk and Bojan Čičić.

No sooner had this opener come to a close than a funky, off-beat, slap-bass-like theorbo line led into the night’s first vocal number: a Monteverdian madrigal entitled ‘Zefiro torno’. Tenors Benjamin Hulett and James Gilchrist blended beautifully in their zephyrean, florid lines – now in harmony, now in antiphony – and both seemed perfectly in tune with the joyous spirit of the text, until an almost Romantic twist, surprising in its harmonic richness, left the singers mourning the poet’s loneliness and isolation. Another wonderfully expressive madrigal, ‘Se vittorie sì belle’, saw all performers emitting genuine happiness in their shared musical experience; this was particularly noticeable with keyboardist Jonathan Cohen, whose engagement with his fellow musicians was tangible in his bouncy, floppy-haired, youthfully enthusiastic direction of the ensemble.

After another instrumental number, a Sonata à 4 by Dario Castello, which perhaps didn’t sparkle as brightly as the Falconieri, soprano Anna Prohaska joined the group for a scene from Cavalli’s opera La Calisto. If her copper-hued shift dress, jet-black sculpted hair and upper-arm bangles reminded me slightly of a sarcophagus, there was nothing mummified about her fresh, light voice, which trickled Cavalli’s notes delightfully over an enthralled audience. I did feel that perhaps she was a touch reserved in her expression; a musical trait that was displayed theatrically in the duet which closed the first half. Hulett’s Eurymachus seemed far keener on Melantho in a love scene from Monteverdi’s Il ritorno d’Ulisse in patria, Prohaska remaining wisely distanced from his passionate outpourings. The vocal blend was once again exceptional, with both singers’ beautifully light, youthful voices coming together, like their characters’ love, in long, exquisite unisons which seeped outwards only to return to the final, softest of endings.

Before the final showdown of the concert, we were treated to two further expositions of the excellence of the Academy’s instrumental ensemble, that transformed Marini’s simplistic Pastorello into a rich and beautiful work, through quietly, unobtrusively passionate and communicative playing. Zanetti’s rustic Salterello, a jolly-good-jaunt of a piece featuring a violin duet over a rhythmically united ensemble, provided an excellent link between Monteverdian madrigals. ‘Ohimé ch’io cado’ saw Prohaska showing both her cheeky and technical sides as she leaped between high and low registers with a perpetual energy underlined by the band.

But the concert’s gamble was to come. Il combattimento di Tancredi e Clorinda, surely one of Monteverdi’s most bizarre pieces, is a tragic tale of love and war, part-recited by the tenor narrator, part-acted by the protagonists, and fully depicted by the ensemble. Monteverdi’s revolutionary writing sees entire sections of relentless, grating, repeated chords – representing war – contrasting strongly with beautiful lyrical sections – representing love.

Above this incredible instrumental schizophrenia, James Gilchrist sang the part of the narrator with true passion, not to mention compassion. His richer, more mature voice contrasted with those of the young lovers Tancredi (Hulett) and Clorinda (Prohaska) – who mistake one another for warrior enemies and fight until Clorinda is slain – and his engagement with the music, words, and audience proved him to be a masterful musical storyteller. Fuelled by battle, touched by love, moved by pity: Gilchrist was truly magnificent in the scope and skill of his extraordinary recitation, and all in the hall could not fail to be swept away by his performance. Thus, the gamble proved to be the concert’s trump-card: thanks, that is, to Gilchrist’s emotive genius, Hulett’s and Prohaska’s beautiful naivety, and the Academy of Ancient Music’s energy, exuberance and downright excellence.