BBCSO / Robertson, Barbican, London

Given that good opera designers have always understood the importance of colour think of Hockney's luminous greens and mauves for Ravel's L'enfant et les Sortilges it's surprising that classical musicians have been so slow on the uptake.

Although conductor David Robertson and his BBC Symphony Orchestra colleagues can present themselves as being on to something "new" with their Painting the Score concerts, they're still 100 years behind Skriabin. For that eccentric Russian composer, all music was to be perceived in terms of colour, and by elaborating his synaesthetic ideas with the aid of a photographer, he took them into mystical realms.

Synaesthesia is cool, and it's actually quite common. The pianist Hlne Grimaud once told me that musical keys had colours for her C minor was black, D minor was blue and it was nice to find the leader of the BBCSO, in a pre-performance talk, corroborating this phenomenon: in his case, E major was yellow, G major green, and B flat minor blue. But Robertson's approach was cultural-historical, drawing on the fact that Debussy chose a Hokusai print for the cover of La Mer's score. Here, each work would be performed with a painting projected onto the back of the auditorium.

Monet's Morning on the Seine was the backdrop for Prlude à l'aprs-midi d'un faune, and Robertson prefaced the performance with a commentary interspersed with musical examples that deftly exemplified his thesis about this work's balance between stability and instability. Monet's Water Lilies triptych served as the image behind Jeux, but that misfired: the colours looked sludgy, and while the music pulsated with life, the painting just projected inertia.

Invited to come aboard Hokusai's boat for La Mer, on the other hand, I found sound and vision melding nicely. The lovely and unfamiliar triptych accompanying the second movement allowed the eye to wander at length, and the giant wave beloved of present-day advertisers seemed perfectly to mirror the swelling and crashing music. You could say, of course, that none of this is necessary music of this calibre carries all the colour it needs but it was worth the experiment.