Bach's religious music is so dominated by religious images and allegory that other hidden meanings are difficult to detect. Here we take one of Bach's secular works - his Goldberg Variations, where there is no religious imagery to obscure the view - and tease out several layers of hidden messages.
Like all intellectuals of the Baroque era, Bach was convinced of the essential 'rightness' of the universe - a belief (to quote another author) in the basic interconnectedness of all things. He believed that words and names reflected the qualities of their objects, and that numbers were a way to show links between different things. He also believed strongly in the value of logic and rhetoric.
These beliefs are actioned in his music, though not always in an obvious way.
Bach's 'New Piano Works'
Towards the end of his career, Bach began to write a series of books of piano works (the Clavierubung series). They were technically complex pieces, and so less popular than previous works, and through them Bach was exploring new possibilities for musical content. He clearly identified the first three books as Volumes 1, 2 and 3. When the book known as The Goldberg Variations was published, the publisher identified it as Volume 4 of the series, a link never made by Bach himself.
Consideration of Bach's belief in the importance of numbers suggests that the book should not be called Volume 4. Here is the evidence: Volume 1 consists entirely of pieces written for a single-manual harpsichord; Volume 2 consists of pieces for a two-manual harpsichord; and Volume 3 is written for an instrument with two manuals plus a foot pedal, and contains several difficult three-part fugues. However, The Goldberg Variations are written for a two-manual instrument, not one with four operating 'functions'.
The Origin of the Title 'Goldberg'
Several stories have been put forward as to the origin of the name for The Goldberg Variations, including ones inventing a pianist called Goldberg... but no such pianist existed.
The book was sponsored (at the time, in secret) by a Count Keyserlingk, an intellectual with whom Bach shared many jokes. It is possible that 'Goldberg' was a code word they used to refer to this sponsorship - a sponsorship that provided Bach with a heap ('berg') of money ('gold').
Numbers, Hidden Symbolism and Structure
In The Goldberg Variations we can see Bach's expression of music as being unified with all things in an ordered universe. He uses numbers, symmetry and structure (rather than melody) to do this, things which would have been known to his contemporaries, but which we have lost sight of. (The same tools are used in all his music, but are more apparent here, where there are no religious overtones.)
The work comprises 32 pieces. All are built on the same 32-note ground bass, with the same rhythm maintained throughout the work. The opening piece (an aria) must have been written several years before the main work was conceived, as it is found in Anna Magdalena Bach's music book, copied in her hand, from sixteen years before. This piece is repeated, with slight variation, as the last piece of the work.
Within the work, the second 16 pieces are in styles that match those of the first 16, emphasising symmetry. Altogether, there are nine pieces in canon form, equally spaced through the series at intervals of three. The intervals between the two parts of each canon increase by one note from one canon to the next. The variations and toccatas are also spaced through the work in intervals of three.
Another Hidden Layer of Meaning
Shortly before this work was composed, a musical critic of the time, Johann Scheibe, wrote a stinging attack on Bach's style of composition. Bach openly stated that The Goldberg Variations were his refutation of that attack. Indeed, in their musical quality and compositional inventiveness, they proved his exceptional ability, and thus refuted the criticism.
The work, however, contains another, hidden refutation. Bach was familiar with the Socratic school of philosophy, and in particular with the style of the Roman orator Quintillian, who documented methods for refuting the false arguments of other orators. Each piece in the work represents one stage in Quintillian's method, even down to ridiculing your opponent at the end of your argument.
In the very last variation - the re-statement of the original theme - Bach inserts two counterpoint themes that were well-known children's songs of the day. Those songs express a child's dislike of vegetables, specifically cabbages and turnips. This was Bach's way of thumbing his nose and saying 'Yah boo! Cabbages!' to his critic.