A lifetime ago, when I was taking a first-year course in music theory at university, the instructor was banging out a series of chords from a Chopin Nocturne – and I speak literally here, he was punishing the piano as though to beat the sequence into submission, as though to – what? force it to reveal its mysteries? But its mysteries did not lie in an argument about the function of a particular chord, an argument that hinged on whether Chopin had written a G-flat when he should have written an F-sharp (the same black key on the piano).
The Nocturne’s mysteries, insofar as they are discoverable, lie in the relationship between the ceaseless rhythmic iteration of the left hand and the right hand’s striving to sustain its long melody notes, and in the subtle dissonances the left hand uses to corral it – language of affect not wholly different from that used by Henry Purcell in “Dido’s Lament”. None of this seemed of any relevance to my chord-puzzle instructor, and shortly afterwards I changed my course.