November 5. Had several musical insights in quick succession which, once you have them, sound innocuous but took me decades to come to. One of them is that the staff looks like a keyboard rotated ninety degrees to add a time dimension. Chords look no more complicated in it than the pattern of keys I press down.

The accidentals switch the staff into a different mode to represent a different scale. Certain keys are exchanged in it, others are missing because you need them less often in this mode.

If I had known anything at all about this, I could have spent years pondering the question of transposing wind instruments. How when you play a C on a saxophone, it mysteriously comes out as a B-flat – even though they simply chose a different notation convention to better represent the range of the saxophone on the five lines, without inventing an entirely different clef, as they did for the viola, for example.

The question of scales is extremely mysterious. If one assumes that there is a system of twelve steps into which each frequency interval from f to 2f is divided, then the naming of tones and scales does indeed seem quite crazy and as if set up to confuse beginners. But music was not, after all, developed deductively from a twelve-tone system. The scales, keys, chords, notations, even the instruments are like a kind of scribbles made during the exploration of the frequency spectrum.