It is a neat trick, and not something that happens often, but I would guess that’s because it’s not useful as anything other than a neat trick. I’m not seeing the eternal golden braid in it, is all.
Actually, if Bach had kept the pattern intact without “crossing the enharmonic seam” it wouldn’t be much of a loop at all; the piece would end up in B# minor after six repetitions.
Yeah, I’m in agreement with you and others that it isn’t the most compelling example he could have chosen.
As to the enharmonic seam thing, that is indeed the point: you either have to cross the enharmonic seam by spelling two identical-sounding intervals differently (in this case, one of the major seconds has to be spelled as a diminished third) or else you have to deny the seeming aural fact of octave equivalence by spelling the return of C as B-sharp. Since composers are extremely reluctant to do the latter, they have no choice but to do the former—a commonplace in the nineteenth century, a bit of a special trick in the mid-eighteenth.
It is a neat trick, and not something that happens often, but I would guess that’s because it’s not useful as anything other than a neat trick. I’m not seeing the eternal golden braid in it, is all.
Actually, if Bach had kept the pattern intact without “crossing the enharmonic seam” it wouldn’t be much of a loop at all; the piece would end up in B# minor after six repetitions.
(edit: sp.)
Yeah, I’m in agreement with you and others that it isn’t the most compelling example he could have chosen.
As to the enharmonic seam thing, that is indeed the point: you either have to cross the enharmonic seam by spelling two identical-sounding intervals differently (in this case, one of the major seconds has to be spelled as a diminished third) or else you have to deny the seeming aural fact of octave equivalence by spelling the return of C as B-sharp. Since composers are extremely reluctant to do the latter, they have no choice but to do the former—a commonplace in the nineteenth century, a bit of a special trick in the mid-eighteenth.