Why this is so, is a question almost best not to ask: why not just bask in the prestige and popularity these concerts in the round have built up? But ask it I will and I will attempt to answer it.

If Classic FM has done its work and sent newly interested classical music fans on to Radio 3, then they will have found a whole galaxy of string quartets and other small ensembles now extant, thanks to a flourishing the young generation. Many are appearing at the Old Market and making their mark. The numbers and the quality are now simply staggering.

In the hours after this concert, Ensemble 360, who have appeared twice during recent Coffee series, were demonstrating, then playing Spohr's Nonet, a work they gave here two years ago and were about to record, on Stephen Johnson's Discovering Music on Radio 3 at 5pm, in a programme made at Ensemble 360's Sheffield Music-In-The Round residency.

Then on Monday, the live lunchtime concert featured Gwilym Simcock, the pianist who is a BBC Radio 3 Young Artiste and a BBC Radio 3 Listeners Award 2008 nominee. In December, he was here with Acoustic Triangle, and on Monday he was with his own trio playing tracks from his new album. Simcock is a classically-trained jazz musician of astonishing facility, still in his 20s and that jazz is now part of the Coffee Concerts' range demonstrates how loosely many classical music fans now define their horizons.

It seem to be a case of classical music also acquiring an element of being media-driven.

There is nothing like being able to see artistes of national radio renown perform a mere feet away from one's seat, and slowly over the last decade, more people are recognising the names and wanting to hear the music. Londoners enjoy this automatically. In the provinces, Brighton is unsurprisingly at the forefront.

To have introduced the first work of the morning and mentioned that the ensemble poised to begin playing knew Hans Keller is something we would not have heard from the mouths of the younger ensembles. Levon Chilingirian and his Quartet studied under the great German classical music luminary of the last century, (a kind of Teutonic, hands-on Donald Tovey) and here we were embarking on a morning of Haydn, Shostakovich and late Beethoven in the hands of established masters, of top-ranking, legendary status and reputation in world of British chamber music making.

Chilingirian himself, the leader and first violin, I first saw in 1971 giving a Haydn concerto with the London Mozart Players in Bromley Town Hall. He related how Keller had talked with them about Haydn's 'difficult' F sharp string quartet and hinted that the Chilingirians were then one of few groups capable of bringing it off.

But what humility. After they had finished, here at Hove, Chilingirian, a smile never far away whenever he speaks, thanked the audience for their response - insisted that they should not allow the performance they had just heard to put them off, but have should a go at playing it themselves.

Any work for strings in F sharp is challenging as the fingering in that principal key does not allow full resonance across the instrument (like asking a guitarist to play in Ab). It has a feel and sound of its own, different, still, to Haydn's Passione Symhony (No 49) in the same key where, of course, oboes, bassoons and horns memorably cloud and colour the work.

To be taken into what for Haydn was a rarified world was clever preparation for the language to come next: Russian, dissident, repressed, 1966, Shostakovich in F minor, Opus 122 No 11. A key next door to Haydn and arguably a darker one still.

Seven short and intense movements, unbroken in sequence, brooding, breathtakingly introspective at times but with a glimpse of optimism in an upward slide on the string early on. The instruments conversed, often two at a time, sometimes three. Grating chords, a moto perpetuo first violin, a sense of the question Why? Then a ghostly staccato, against which the slide returns - ironically? A jabbing rhythm, and then, sooner than expected, the end, the fnal words, with Chilingirian holding a high, high top note, like a distant, fading light.

Utterly compellingly played, and yet, the Chilingirians were merely showing us one of their many mature suits of foreign clothes.

The interval: sherry or fruit juice on the house, or coffee or tea, plus Janet Lawrence's stunning range of morning cakes rightfully paid for. Then into the last string quartet of the season. Beethoven in Eb Opus 127.

The sound of this key is miles away. Beethoven is deaf but in radiant mood (that's why he chose Eb), he has completed Missa Solemnis and the Choral Symphony (his last works to gain universal popularity). Now he is pushing his personal language boundary out like a boat across just-discovered straits.

But, as wonders Clifford Bartlett, the writer of the Coffee Concerts' excellent programme notes, Beethoven may not have realised this phase of his composing and his life was the last boat. And that the tide, once turned, would not be coming back. I guess Ludwig did sense this was so.

The effort of it all, the frustration, the exhaustion, his wearisome and unendingly demanding worldly affairs. Something had to give. But he knew, for sure, that what his pen was putting down on paper spoke of and became a world he had already reached - remotely and utterly alone.

Cellist Philip de Groote, violist Susie Meszaros and second fiddler Charles Sewart rowed Beethoven's boat in perfect co-ordinated rhythm, with great power and a surging inevitability. And at the prow was Chilingirian, outstanding in his delivery and assurance, pointing the way into the uncharted, and casting confident light onto the dark unknown.

The next year, Beethoven was dead.

The Coffee Concert grand finale is a piano recital by the 1992 BBC Young Musician of the Year. Freddy Kempf will play Bach's sixth Partita in E minor, Busoni's working of Bach's Chaconne in D minor, the Chopin Sonata No 2 in Bb minor which includes his celebrated Funeral March, and Rakhmaninov's second Sonata in the same key.
Sunday, May 25 at 11am, tickets from 01273 736222.

Dates of the 10th Coffee Concert Series: October 19 2008, November 30, December 14, January 11 2009, February 8 and 22, March 8. Tickets can be booked from April 1.

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