Few composers can have delighted more than Bach in patterns of all kinds. Those in today’s programme fall into several overlapping categories. One is canon, the technical device where a tune fits neatly with itself played at the same time but slightly later (and possibly upside-down, or at a different speed). There is Bach’s systematic exploration of fugal technique, the ‘Art of Fugue’, written right at the end of his life; and there is symbolism of various kinds: pictorial representation of theological truths in chorale preludes, or numerological symbolism such as that referring to the Trinity.  

Today’s programme is framed by the mighty Prelude and Fugue in E flat, movements written to bookend Bach’s great 1739 series of chorale preludes, Part III of the Clavierübung (or ‘Keyboard Exercises’). That collection is based around the Lutheran catechism, the exposition of religious faith as Bach professed it, and central to it is the declaration of God as Father, Son and Holy Spirit. Thus the number 3 plays a major role: partly in the unusual key signature of three flats, but also in the structure of the music – there are 3 ‘blocks’ of music in the Prelude, which cycle around, and three sections to the Fugue (thus a ‘triple fugue’). This is music of grandeur, profundity and brilliance, opening in the march-like ‘French overture’ style that was used for the entrance of a monarch (in this case, the divine King. 

Next, two chorale preludes from within the collection. Christ unser Herr is a setting of a hymn about Christ’s baptism in the River Jordan. Bach uses pictorial representation here: running semiquavers in the LH to depict the stream, two overlapping parts in the RH using a ‘cross’ shape to represent Christ himself, and the tune through the middle, played in the pedals. At the moment that the tune enters, the ‘cross’ figure (Christ) briefly descends below the waves! Dies sind is concerned with the Ten Commandments and it is therefore perhaps no surprise that the tune, when it enters in the LH, is treated in canon, that ‘rule-based’ technique. However, one might conclude that Bach considered the commandments to be the route to a happy and fulfilling life, since he encloses this canon within three more parts of delightfully relaxed and pastoral serenity. 

Canon finds perhaps its most thorough treatment in the remarkable Canonic Variations on the Christmas hymn ‘Vom Himmel hoch’ (‘From heaven above’) written by Bach in 1747 for the ‘Learned Society’ of his former pupil Lorenz Mitzler. There are five variations employing all manner of intricate canonic devices, beginning with the fluttering down of the angels with the Christmas news, and ending with joyous pealing of bells. The last variation alone uses canon in multiple different ways; and along the course of the variations Bach more than once weaves in his musical ‘signature’ (the notes B-A-C-H equalling B flat-A-C-B natural in English notation). 

Bach’s magisterial treatise on fugal technique, Die Kunst der Fuge, was written towards the end of his life and left tantalisingly incomplete at his death in 1750, breaking off at the climactic moment. No particular instrument is specified, but the work lies well for keyboard and lends itself to arrangement. Today we hear three contrasting movements: the opening one, the most straightforward, on the theme of the whole piece; then a canon on a decorated version (the Art of Fugue, needless to say, includes several canons); and finally an athletic fugue on a different theme (in running quavers) which before long combines in various ways with the main theme. 

After such intellectual rigour, a couple of gentle chorale preludes from his collection Orgelbüchlein (‘Little Organ Book’) from much earlier in his career, which presents settings of chorales for use throughout the church year. Both are for Passiontide, the season commemorating Christ’s suffering and death. In O Lamm Gottes (‘O Lamb of God, sinless’) the tune is again treated in canon (between the pedals and the alto voice) but the mood is set by the other parts which employ the ‘seufzer’ or ‘sighing’ figure traditionally associated with melancholy and suffering. O Mensch, bewein (‘O Man, bewail your great sin’) is one of the most celebrated of Bach’s chorale settings, being of the utmost expressivity and, in the closing bars, remarkable chromaticism (including a rising bass in which some have seen Christ’s walk to the cross). 

And so back to the E flat Fugue to finish: overall, a variety of forms and genres, whether practical or theoretical in aim, and a glimpse into Bach’s rich and distinctive world of pattern, order and meaning.  

David Goode (c) 2026