On this side of the Rubicon, I hear most pieces that are written in common keys a semitone up from the start. Not all keys are like this yet. F major does not have this feature, presumably because F sharp major, a semitone up, is a key less characterized in my cerebral wiring. Likewise D minor doesn’t yet shift to E flat minor on most occasions. but for a majority of keys there is no period of equivocation – the ‘voice’ is a semitone up ab initio. C minor, that strong fateful key, has also proved to be more stable, perhaps because C sharp minor is another lesser known key to my wiring.

Yet A flat major seems to equivocate. Yesterday I was surprised to hear Chopin’s piano Ballade in A flat major start and stay in key until I had to switch it off as I arrived at my destination. Now the A flat major slow movement of Mozart’s 39th symphony started and stayed up a semitone in A major with no equivocation. I was a little surprised at this fickleness as this wonderful movement with its imaginative use of the wind instruments has been an A flat major favourite since my teen years.