Rehearsals can become addictive and, in recent times, I have twice had the pleasure of watching Edward Gardner working with the City of Birmingham Symphony Orchestra, preparing performances of works by two of this year’s notable musical centenarians, Benjamin Britten and Witold Lutosławski. It is in the nature of things that all composers are outlived by performers who knew them personally and worked closely with them; and whose continuing advocacy is crucially important in the difficult, potentially fallow, years that always seem to follow the demise even of the most celebrated creative artists. Mstislav Rostropovich and now Sir Colin Davis are lost to us, but last month’s historic Peter Grimes, both in Snape Maltings and, altogether more remarkably, on the beach at Aldeburgh against the backdrop of the North Sea, reminded us that Steuart Bedford is still going strong, 37 years after the death of his mentor, bringing special authenticity to what, by any standards, was a brave gamble.

Ed Gardner is simply too young to have known either Britten or Lutosławski personally, but he is at the vanguard of a new generation of first-rate conductors who are breathing new life into their works in concert hall, opera house and recording studio. Rehearsing Britten’s War Requiem in the majestic setting of St Paul’s Cathedral, magnificently indifferent to the to-ing and fro-ing of tourists and burly gentlemen who wanted to move around row after row of metal-framed chairs, Gardner remained endlessly affable as he battled against the man-made impedimenta to his craft. Watching him at work, it is impossible not to reflect on how far the orchestral world has moved on since the days of the tyrants and martinets – the era of Szell, Reiner and Karajan, when the man on the podium eschewed affection but demanded respect.

There isn’t a shard of the autocrat in Gardner. Although he shares an alma mater with our current Prime Minister (and numerous others), early privilege has seemingly made him humble in success. No one can question his musical mastery, which seems to be allied in him not with the arrogance of the born master, but with the kind of quiet self-confidence that belies itself, manifested in a spirit of amiable collegiality. He treats his colleagues as just that – colleagues. Soloists and orchestral rank-and-file alike are treated with courtesy and respect.

His approach to the notorious St Pauls’ acoustic is commendably pragmatic. The boys’ choir is hidden but hauntingly audible; the soprano soloist is placed where we can hear her, any dogmatic obsession with seeking to replicate the curious effects Britten achieved in his recording of the piece having been dispensed with; and, working with Gardner, the virtuosic timpanist in the chamber ensemble achieves a near miracle in mastering the acoustic under the dome. Indeed, it is all easier for the chamber ensemble, with its astringent scoring, than for the full orchestra or the singers. By the end, however, the soloists are perfectly balanced and the choirs, as choirs can do in an acoustic designed for them, sound both breath-stoppingly beautiful and yet also chilling, when required. Toby Spence, currently in the middle of his impressive run as the favoured but ill-fated Earl of Essex in the Covent Garden revival of Gloriana, is the stand-out soloist. Gardner captures perfectly what he describes as the ‘filmic quality’ of Britten, combining grand gestures with the intensely personal. He also revels in conducting both orchestral ensembles – acknowledging the ‘two strictly defined roles’ but adding that ‘I love the fact I have a connection through the whole piece’.

Gardner is no less persuasive a Britten advocate in the recording studio, as his well-received series on the Chandos label testifies. On the same label, a more comprehensive series of hybrid SACDs devoted to the major orchestral pieces by Witold Lutosławski provides ample evidence of his command of the uniquely bewitching textures, melodies and harmonies that characterise the music of Britten’s Polish contemporary. I turn to those recordings again and again, not least the single CD devoted to vocal music, which features both Toby Spence and also Lucy Crowe, who is again the soloist in the song cycle Chantefleurs et Chantefables when I attend a CBSO rehearsal in the highly contrasted acoustic of Symphony Hall in Birmingham. The early part of my Lutosławski pilgrimage this year was heavily populated by those who knew the composer well and worked closely with him – Antoni Wit, Anne Sophie Mutter, Krystian Zimerman, Miklós Perényi and the ever-green Stanisław Skrowaczewski, approaching his 10th decade in sprightly fashion – but this is very different. Gardner is a vigorous and evangelical proponent of this music. ‘His music will last,’ he once told me. ‘There’s no doubt about it – for me, I will do it for the rest of my career’.

He attributes the unique Lutosławski sound-world principally, but not entirely, to the passages of aleatoric music that the composer pioneered: ‘The way these free parts sit together, it’s a law of amazing probability ... It makes all these individual string players, all these individual woodwind players, play with such character and body – soloistically ... There’s something about standing in front of the music which you don’t get with anyone else, whether they compose in an aleatoric way or not’. Touchingly, he appears to be as disappointed as I am that I have missed the rehearsal of the Third Symphony, his personal favourite, whose ‘very visceral’ qualities he admires and brings superbly to the fore in his recording with the BBC Symphony. The enchanting cycle of vocal miniatures that I am able to hear was one of the composer’s last works and perfectly captures the more demotic, lighter and more accessible idiom to which he directed his efforts in his final decade or so.

I last heard the work in the Royal Albert Hall, but here in Symphony Hall the delicacy and sheer wittiness of the scoring is incomparably more apparent. I hear every flutter of a butterfly’s wing, every primeval groan of the grumpy alligator denied his prey and every clump of the tortoise. Gardner gives full weight to every detail and every syncopation, relishing the final, unexpected flourish of Lutosławski’s distinctive aleatoric method in this late, late work. He also explains the fleeting, slight and surreal tale each song tells, prompting hoots of amusement and delight from the players. This ability to attend to detail, whilst also ensuring the whole exceeds the sum of its parts, marks out the great conductors. The sheer translucence Gardner achieves in this piece, matched at every turn by this fine orchestra and Lucy Crowe as a wittily acute as well as technically flawless advocate of the texts, makes me want to hear more of him in the concert hall. And in rehearsal. A lot more.