Passing the time between a rehearsal and a concert, Bob and I walk along Wigmore Street. We spot a shop selling all kinds of accessories to do with wine drinking. We pop in for some vacuum corks. Inside the shop is a display of luxurious wine glasses: hand-blown, ultra-thin and balanced on stems so long and fine they look as though they would snap in your hand as you twirled the glass. Peering at the price tag, I see ‘£90′. I ask the salesman whether this is for a set of six? ‘No, it’s the price of a single glass.’ Never have I heard of such an expensive glass, so I ask what is special about it. He explains that it is hand-made from very pure glass with a high lead content, and that this makes the glass slightly flexible.

To my astonishment he then takes a large glass off the shelf, pinches its rim between thumb and forefinger, and presses slightly so that I can see the glass flexing. For some reason this is intellectually disturbing, like the scene in Flann O’Brien’s The Third Policeman where the narrator is shown a series of little carved chests made by policeman MacCruiskeen, each chest smaller than the last until they become too small to be seen by the naked eye. A flexible wine glass is something beyond my ken. ‘Does the quality of the glass have an effect on the experience of drinking the wine?’ I wonder. ‘That is like asking whether a fine violin has an effect on the tone,’ he answers smilingly. But is it?