Fountain, a professor at London's Royal Academy of Music, had in a book of music stumbled upon something unexpected, he said, while rooting out a version for left hand of a Bach Chaconne. Fountain was here to play one of Mozart's less-often heard Piano Concertos, to provide a more serious pre-contrast to the relaxing and smiling Straussian waltzing, galoping and polka-ing that Gibbons had selected for this year.

The Mozart was to be his C minor K491, the second of his mere two in a minor key. In his customary introduction of the audience to the music, Gibbons gladly offered them the chance to guess the composer of the cadenza Fountain had found in this book, written specifically for this concerto, and which he had learned for insertion in this performance.

The moment arrived, late the first movement, at which point Mozart had left behind for the performer only the angry lead-back to the orchestral finale from the player's intended extemporisation on some of the themes heard thusfar.

What clues revealed themselves? Pretty soon came some crossed hands. Some low left-hand bass work might have been Beethoven - indeed he wrote a now well-used cadenza for the only other Mozart minor key concerto, K466 in D minor.

But the music increased in an harmonic richness probably beyond Beethoven's time. Could it be Brahms? Aha, I sensed an itching to insert some double octaves and, yes, here they came and, further on, some ideas played characteristically across the rhythm.

My companion thought it Schumann, and he was close. But Brahms it proved to have been, and Fountain has in his hands a fascinating and attractive tool for his performance of this, probably Mozart's greatest piano concerto, because Brahms is not a name quickly connected with Mozart in the public mind*.

Fountain's reading of the whole work was restrained and controlled, and he allowed the extra depth of sound and the flat keys to speak for themselves. His right-hand octave leaps in the first movement came as reticent sighs and his overall interpretation created a sense of regret and pathos between the mountings of turbulence.

He kept decoration to a minumum, which is judicious in the slow movement, where Mozart's raw material is potently simple and direct. And in the finale he led the way into the Mozart's disquietingly original angles and caprices. But his final cadenza was completely minimal, as if to preserve until the end the sense of restraint, the rejection of fuss or extravagance and the projection of the pure.

Gibbons let the horns ominously threaten in the opening and he offered some excellent orchestral detail in the finale.

The after-dinner menu of dances, selected and introduced with fun and illuminating references to Viennes life by the popular Gibbons, was prefaced by Franz Von Suppe's overture, Morning, Noon And Night in Vienna, intelligently picked by the conductor as it is a kind of scene-setting tone poem for what was to come.

Orchestra librarian and double bass Eddie Hurcombe had suggested to Gibbons the inclusion of the Bohemian Jaromir Weinberger's Schwanda The Bagpiper. Its familiar melody was unmistakeably Bohemian and served as a reminder that the neighbouring nations surrounding Vienna lend their own flavour and lilt to shape "the sound of Vienna". It is inevitably a cosmopolitan concoction.

Perhaps the audience might have liked to have done a little more clapping, but maybe Gibbons will let them let their hair down earlier in next year's annual proceedings.

Four concerts take us towards spring (all 2.45pm):

• February 3: former BBC Young Musician, Anna Markland plays the Gershwin Piano Concerto with Gibbons and the excellent West Sussex Youth Orchestra, who bring Rakhmaninov's Second Symphony and Walton's catchy Johannesburg Festival Overture.




• February 17: the Alassio Orchestra and conductor Marcus Martin with a programme of Vaughan Williams, Butterworth, Sullivan, Ivor Novello and his brother Glenn Martin's Fantasy on Spanish Themes for saxophone and orchestra in its UK premier.




• March 9: the WSO return and leader Julian Leaper plays in TV composer Nigel Hess' hugely popular Ladies In Lavendar film suite. Emergence from winter will be echoed with Delius' On Hearing The First Cuckoo in Spring, Copland's Appalachian Spring (with its Lord of the Dance tune), Vaughan Williams' pastoral Five Variants on Dives And Lazurus, and Schubert's lightly charming Fifth Symphony.




• April 6: the climaxing concert with the WSO's own Russian violin sensation discovery, Boris Brovtsyn, delivering a double whammy with Lalo's Symphony Espagnole and Frank Waxman's Carmen Fantasy. Then it will be Tchaikowsky's Fourth Symphony.

*Watch this site for an article to follow about this cadenza, Brahms and Mozart.