Stephen Kovacevich 70th Birthday Concert, Wigmore Hall

Heartfelt birthday salutations to the great pianist first known as plain Stephen Bishop. For a recital in the early 1980s, when he first added the paternal Croatian "Kovacevich", introducing me to late Brahms piano music - Op 117, never more evanescent or troubling since - and the Beethoven Tempest Sonata, an incentive to tackle that work as best I could.

For many unbudgeable CDs on the shelves, including the great duo partnership with one-time other half Martha Argerich and late Schubert sonatas. And for having the characteristic modesty, last night, to give a protégée the central spot in a heavyweight programme, inspiring some of us and infuriating others.

That was clearly quite an achievement for the 23-year-old Georgian pianist Khatia Buniatishvili (pictured below by Julia Wesely), given that the line-up also included the star attraction, for many, of the elusive Argerich - surely Buniatishvili's role model as well as co-mentor - the front-rank young Belcea Quartet and percussionist of the year, Colin Currie. But then Liszt's B minor Sonata, despite its brief rays of light, is an infernal piece in every way. Had the piano tone been even slightly less phenomenally full and rich, I'm not sure I'd have gone with Buniatishvili's charge into the flames, all demonic Bengal Lights and Catherine Wheels.

Liszt's essential lines, if not every note, remained clear and imposing, and in the serene slow music that gives much-needed introspection at the heart of the work, Buniatishvili underlined the profound musicality which some in the audience subsequently seemed intent on denying her. Could she possibly keep the devilish ensuing fugue going at the speed with which she started it? She did, and drove on to a finale of ambiguous redemption in which all the strands truly came together. But what I'll remember most is the way that sound hit me full in the stomach, reaching right to the back of the hall - truly the shock of the new.

There was something of that in Kovacevich's partnership with more questing youth, the players of the Belcea Quartet. With Kovacevich, Brahms always seems subtly subversive, and that was especially true of the ornamented walking pace he set for the second movement of the F minor Piano Quintet. The schizoid scherzo began with barely audible but tense drama from the Belceas before its exultant explosion; the tragic intrusions of the finale were especially startling in context. The Wigmore sometimes has a habit of cowling and muddying piano sound, but Kovacevich's habitual lucidity was never daunted for a moment here.

Even so, this wasn't the venue to suit Bartók's Concerto for Two Pianos and Percussion, clever though it was to link that daunting work with its Lisztian roots. I could see that both Argerich and Kovacevich (pictured left in their early Philips recording) were doing their stylish best with nuance, and some extraordinarily trenchant timpani work from Currie was complemented by ear-tickling xylophony from Sam Walton. Yet the crispness and sharp attack of the Argerich/ Bishop-Kovacevich recording wasn't recreated here, and for that the hall's acoustics as well as the cramped impression of those four players plus a couple of harrowed page-turners on a microphone-strewn platform was surely to blame. And it was certainly a dense programme; never did the audition question "Did you bring any Mozart?" seem more apt. In fact the only light touch was senior house manager David King's compering skills, reaching their peak as he dared to commandeer Saint Martha's piano for a rousing "Happy Birthday" coda. Here's to the next 10 years.

Watch Stephen Kovacevich playing the opening of the Brahms F minor Piano Quintet, Op 34, with a distinguished quartet at the Verbier Festival on medici.tv:

• The concert will be broadcast on BBC Radio 3 on 25 October
• Don't miss Khatia Buniatishvili's lunchtime recital at the Wigmore on 1 November
• Find the Kovacevich/Argerich duo disc on Amazon
• See what's on at the Wigmore Hall this season