When I was putting up an Inquisitor on the weekend this puzzle appeared, I kept away from one called Passacaglia with Variations, because I was sure it was already there.  And it isn’t – I will put it up fairly soon.  It’s a further example of moulding a musical form into a puzzle idea.  As I’ve noted elsewhere on the blog, I do see a lot of connections between music and crosswords.

So a second venture into musical form isn’t unexpected.  The reasonably rigorous structure of a fugue also make it a likely choice to project on to a grid.  The question always was how.  Fugues are very linear and grids very square, so how was I to ensure enough space to have several statements of a theme – hard to claim it’s a fugue if there are only two entries (though two-voiced fugues aren’t unknown).  Would the grid have to be 18 columns by 8 rows?  (Indeed, now I’ve started thinking along those lines I wonder whether there’s merit in a circular grid, with the fugal entries winding round and round indefinitely.)

In the end there was Bach, and BACH.  Many people know that there are eight notes in an octave – the end points are called the same, while the other notes progress alphabetically, cycling through A to G.  And thus you can play BACH on a keyboard, given that German notation decided to call B flat B (I have never discovered why, exactly), and needed a letter for B natural, and settled on H.  There’s also an S, which is the other common flat, E flat (more of that anon).

There are fugues on BACH, not least by J S Bach himself, while the Wikipedia page linked above gives a substantial list of later works, many of them fugal (that by Liszt being the most famous, I reckon).  And four entries of a four-note theme had a certain squareness about them.  Deciding on knight’s moves I drafted a blank grid with four lots of B-A-C-H structured as in the final version – and, yes, that worked.  All that was left was to build the grid around them – and Herr Goldberg, of course, as a final eight-letter touch.  Maintaining the knight’s move pattern used for BACH immediately brought the D and B together in the middle, so I even had a good hint as to where to put a bar…

The next thing was to ensure that no-one missed the theme.  There may be some who, faced with a puzzle called Fugue, and the names Johann Sebastian, immediately think of the surname Cholmondeley, but probably not many, so those names plus ‘knight’s move’, plus saying where the Bs were would probably do it.

One not exactly final touch (since it went into the grid construction) was to include another musical monogram, that belonging to Shostakovich – D-S-C-H, which sits in the bottom left of the grid, also in knight’s move form.  Shostakovich, of course, wrote a set of Preludes and Fugues with many links to Bach, so it seemed right to squeeze him in.  And that, in turn, if I had but put up that early Inquisitor puzzle would bring us full circle.