How do you get more people interested in classical music? It’s a difficult question, but I’d never have guessed it was difficult enough to give to Sherlock Holmes. But sure enough, last Sunday night saw the crowds flock to an oboe quartet recital in a small Wimbledon church, and while they may mostly have been there to see Sherlock star Benedict Cumberbatch read some poetry, they also gradually became one of the most genuinely engaged and enthusiastic audiences I’ve ever been a part of at a classical concert.

The music itself wasn’t an obvious sell, featuring compositions for oboe or cor anglais with string trio by Mozart, Britten, and lesser-known 20th-century composers Jean Françaix and Elisabeth Lutyens. Cumberbatch’s cameo, sneakily rescheduled to after the interval, involved prefacing each of Britten’s Six Metamorphoses after Ovid with a reading of the corresponding poem, meaning that he was on stage for around 15 minutes. But what was really remarkable about this was that the audience absolutely stayed with it after he left. The Britten pieces were followed by three movements from Françaix’s Cor Anglais Quartet, which sounded rather like a sillier version of Poulenc, but they were a major hit. And so was the Mozart Oboe Quartet, which concluded the programme, and was applauded raucously between movements out of sheer enthusiasm.

A lot of the credit for this success must go to the Britten Oboe Quartet, who played as excellently as one would expect but also approached the evening with palpable good humour. Nicholas Daniel’s jocular introductions to the pieces, including his acknowledgement that the rather dense Lutyens piece might be a bit of a struggle, helped things along well – but Daniel is an even better communicator musically than verbally, and these were performances to remember. The opening Mozart fragment for cor anglais and trio, which uses the melody more familiar from the “Ave Maria” motet, shone especially, and the wide variety of tones Daniel drew from his cor made for a more sonically varied Mozart performance than is the norm. The Lutyens piece, O Absalom, was given a tender, pensive reading, though musically its very straight-laced expressionist style has not aged well.

Britten’s early Phantasy Quartet also sounded excellent in these performers’ hands. It’s a rather surprisingly neatly structured piece, given its title, with a clear symmetrical frame including a lengthy central section for string trio alone. The outer sections show a clear Stravinsky debt, with the lightly march-like opening highly reminiscent of The Soldier’s Tale, but as ever Britten finds something new to do with these familiar sounds. The Britten Oboe Quartet are principals in Britten Sinfonia, and their assuredness with Britten’s music was very clear.

Things reached fever pitch straight after the interval, when Benedict Cumberbatch took to the stage with Nicholas Daniel for the Britten Metamorphoses. Cumberbatch seemed a little unsure of himself at first, maybe a little embarassed that his minor role in the evening’s proceedings had had such an enormous effect – but he settled in superbly, providing the perfect foil for Daniel’s impassioned performance of these six short pieces. Remarkably, each one of them – though all only a couple of minutes in length – received a round of applause. What’s more, the two or three of these miniatures with light, throwaway endings – the sort of thing programme notes usually describe drily as “musical jokes” and yet don’t sound very funny – actually made people laugh. This wasn’t just a starstruck audience; it was an engaged one, listening hard.

The level of enthusiasm didn’t abate after Cumberbatch was gone, with the Françaix and Mozart pieces beautifully played and warmly received. But the best was left for the encore, for which Cumberbatch returned to the stage and read Eichendorff’s poem Mondnacht, before the quartet gave a gorgeous rendition of an arrangement of Schumann’s famous setting.

Roping in celebrities is probably not a sensible long-term way for classical music to move forward, but this was an example where it really, really worked. As it happened, a Greek girl sitting next to me was there because she was a Britten enthusiast, and had never heard of Benedict Cumberbatch. When I explained what was going on, she said: “Oh – is this not normal?” and gestured to the hordes of keen, happy young concertgoers around her. We live in hope.