Adjusting the piano stool to the right height for a concert may seem the simplest thing. When I finish rehearsing in a concert hall, I always leave the piano stool adjusted to the right height. The more old-fashioned piano stools have wooden handles that are quite hard work to turn, and I don’t want to have that strain on my wrists immediately before I perform. The newer piano stools have a ‘release’ mechanism operated by a handle under the seat. You reach under the seat to move the handle and allow the seat to move up or down. For best results, you shouldn’t have your weight on the seat. It’s not easy to reach under the seat, take your weight off the seat and adjust the stool without looking clumsy, and you don’t want to start a concert like that.

If I know that a piano tuner is going to be on stage between rehearsal and concert, I always ask them to leave the stool as it is. They always say that they are mindful of doing so, because they know how sensitive pianists are about such things.

So the stool is left at the height which seemed perfect at 6pm. Lo and behold, when I come back on to the platform at 7.30pm, the stool suddenly seems too low. I end up having to adjust it in front of the audience.

Why does this happen? I’ve tried to think of explanations, such as that between rehearsal and concert I have changed my outfit. But in truth there can be no meaningful difference between the thickness of, say, jeans and the thickness of smart black trousers. Even the difference between the fabric of trousers and of a concert dress is minute.

The different must be psychological. When I come on stage to perform, I must be in a different frame of mind.  More sensitive, more picky, more neurotic? Secretly embarrassed and looking for something to fidget with? Trying to put off the moment when the performance begins? Feeling ‘small’? Is it to do with a subtle change of posture caused by performance adrenalin?

I suppose any of these may be possible, though actually, it doesn’t feel like that. It just feels as if the piano stool was fine at the rehearsal, but is too low at the concert.