A closer parallel exists in what one might call the philosophy of pianism, and one which raises a lot of hackles. Charles Rosen, the pianist and peerless writer about music, strenuously maintains that the engineering of the piano precludes a whole host of things that pianists are taught to believe in, and centrally, the notion that a pianist can have such a thing as a "touch". As Rosen himself has put it, "You push a piano key down, and it is louder and softer, and longer and shorter. There is nothing else you can do to an individual note that makes the slightest difference to the music. It is the way the notes are combined by the pianist that makes a beautiful tone." Yet, talking to pianists with whom I work, they are, regardless of Rosen's reasoning, absolutely committed to what must be, from a purely physical and mechanical point of view, a metaphorical way of thinking. Somehow, it helps to pretend that something is happening that can't be.

I've always realised that there is a physiological basis to vocal production, of course, while at the same time finding it too confusing an idea to handle in detail. Intellectually curious as I like to think I am, books about vocal physiology - rather like books about personal finance - have tended to confuse me and make me blurry-eyed. But now I'm going to a singing teacher who (and this is a rarity) works closely with a laryngologist and a physiotherapist, who can tell me things about the relationship between the various parts of the vocal mechanism without sending me into a Weberian tailspin. I think it was Max Weber who said that if you think about how to walk, you fall over.

My teacher's most interesting general point about the vocal mechanism is that, unlike the piano, it is not designed for the purpose with which we most associate it. The primary function of the vocal tract is as one of several lines of defence against choking, that elemental confusion of the trachea and the oesophagus, the windpipe and the foodpipe, a nasty consequence of the evolutionary economy of the human animal. If I've understood him properly, much of what we do as singers, particularly in achieving the high notes which technique facilitates, is actually about persuading the body that one is not about to swallow as one reaches for the skies. And with that rather excrutiating physical image I leave you.