Few pianists have the range or the chutzpah to take on a series of concertos by Rachmaninov, Lutoslawski and Schumann in one week, let alone chamber music by Brahms, Dvorak and Kurtag and a solo recital of Grieg and Liszt. Even fewer could make each of these voices distinct and valid. Norwegian pianist Lief Ove Andsnes – a true genius of the keyboard – is one of the handful who can, which is why I was amazed to see the Barbican at half capacity for the opening concert of his Artist Portrait series. I'd heard that the Lutoslawski was selling slowly. But Schumann, Beethoven and Britten? With the LSO? Where was everyone? Maybe the music-lovers had decided to join the theatre-lovers in an attempt to reanimate the West End. Or maybe it's simply that American maestro Michael Tilson Thomas is a far from obvious choice for Schumann or Beethoven.

Tilson Thomas's forte is the buzz and brilliance of broad New World vistas, not the agitated intimacy of early Romanticism. Sure enough, his Egmont was quite the oddest I've heard. It nearly didn't happen at all: with nary an up-beat, his splayed fingers sliced through the air to be met by a nanosecond of total silence – the conducting equivalent of being caught in public with one's trousers unzipped. As the players slid in to what should have been a shocking blaze of unison, the first theme emerged as the kind of sumo wrestler andante that even Karajan might have raised an eyebrow at. Were these dots or double dots? Not until the LSO's timpanist took charge was there any sense of metre. In less experienced hands this would have been a disaster, but Tilson Thomas is a consumate showman and the orchestra – though obviously unnerved – rescued him. A rocky start was turned into a self-concious slow burn, though only in the heat of the coda did this overture have anything approaching the kind of impact it needs.

Naturally things improved vastly as Andsnes effectively restarted the concert. Andsnes's Schumann is something that has to be heard to be believed: a beautifully weighted, lucid legato where the leaving of the notes is almost more communicative than the way in which he first sounds them. His hands – seemingly too slim to produce such depth of sound – rarely lift more than a few inches above the keys. His articulation is entirely led from the fingers. There's no beefiness from the shoulders, no propelling of the music through extraneous gesture. His phrasing is so calm that you forget that his speeds – particularly in the allegro vivace – are blisteringly fast. And his voicing of what Liszt described as "a piano concerto without a piano" is unique: half soloist, half accompanist. It was just a shame that when you peered over the piano lid you could still see Tilson Thomas's increasingly desperate posturing. He did the jockey thing (riding an invisible racehorse), and the double-handed baseball swing (most odd with a baton), and pulled more sporting poses than the stick figures on the back of those funny biscuits I remember from childhood. And I really wouldn't go on about this so much but for the fact that the off-beat orchestral interjections in the final movement are incredibly difficult to get right and were, in this case, entirely the product of the extraordinary co-operation and understanding between soloist and orchestra.

I don't know whether it was simply relief at being back in the 20th century, but Britten's suite from The Prince of the Pagodas was excellent. Tilson Thomas conducted with ease and élan, even though ballet music without dancing is a hard thing to stomach in the concert hall, Stravinsky excepted. I still don't enjoy Britten's parodies: the King of the West is to twelve-tone what the Rude Mechanicals in A Midsummer Night's Dream are to early Verdi. But the peformance bodes well stylistically for the rest of Tilson Thomas's dates with Andsnes. Let's just hope that Andsnes gets the kind of audience he deserves. Playing of this brilliance is a rare, wonderful thing.

If ballet music without dancing is hard to stomach, how much harder is it to watch dancing applied to music that would be better off without it? At Fretwork's performance at the Union Chapel – a trendy affair with moody lighting and lots of choreography – I found the answer: exogenous dancing is far worse. There are several things I should say before getting to the performance itself. Firstly, that I love this group; I love their timbre, I love the way the individual styles of the viol players tussle against and inform each other, I love the tension of their approach and the sound they create. Secondly, that I know nothing whatsoever about dance. Thirdly, that – given the previous statement – it's only natural that I still know what I like and it isn't the kind of over-literal interpretation that results in dancers lining up a series of ownerless shoes during a work about the holocaust, or squiggling their fingers up to the sky and then tapping their chests to the words "Heaven is mine".

Enough of that, let's look at the music. Constructed loosely around the theme of grief, Fretwork's contemporary/renaissance programme had the visceral attack that Tilson Thomas's Egmont so badly lacked. If the harmonic invention – or lack of it – wore thin in Tavener's The Hidden Face and Orlando Gough's Birds on Fire, this was compensated for by the weird coolness of Tan Dun's A Sinking Love and Andrew Keeling's Schulhoff-indebted Afterwords.

Guest artists Nicholas Daniel (oboe) and Michael Chance (counter-tenor) gave charismatic performances that were beautifully attuned to the timbre of the viols. But little of the new music had the tailormade fittingness to these specific instruments of the Gibbons Pavan.

Wonderful playing, distracting presentation, uneven material.

a.picard@independent.co.uk

Lief Ove Andsnes – Artist Portrait, continues tonight, 7.30pm, at the Barbican, London EC2 (020 7638 8891)