Bach’s Goldberg Variations, in fact, represent one of the most brilliant examples of the far-reaching overturning of the most traditional canons of the varied theme as conceived by instrumental virtuosi in the eighteenth and nineteenth centuries and the advent of a wholly new concept of the genre. As Alberto Basso so rightly wrote in his Frau Musika, in the case of Bach ”the prodigious attention to musical construction and the immaculate impulse to range through all the grades of speculation into the system of sounds and their organisation in geometrical and symbolic concatenations which had so filled Bach’s mind in the previous ten years drove him to seek the solution to this question and led him to set up a new principal of construction which tore up and dispersed the system that had been adopted previously.” The Goldberg Variations BWV 988 are one of the highest moments of this particular approach by Bach, where the composer’s esprit de géometrie is blended with a conception of the variation that goes well beyond the limits of the typically ornamental model in which it was generally understood at the time.
Bach wrote two sets of harpsichord pieces, both entitled Clavierbüchlein, the first in 1772 and the second three years later in 1725, for his second wife Anna Magdalena. Alongside various single pieces that were not used again, the collections contain the first drafts of works that were later to become parts of other important collections, like the French Suites and the Well-tempered Clavier.
This is seen, for example, in the Praeludium in C major (track 37) which will be found identical at the start of the first volume of the Well-tempered Clavier; in the Aria in G major (track 36), which, with some variants, will be the starting point for the Goldberg Variations; and again in the chorale Wer nun den lieben Gott (track 34), which will be found again in a later manuscript collection of chorales.
Other pieces are works by various composers: in some cases they are composition exercises of Bach’s children - like the Marche in G major Anh 122 (track 35), which may be attributed to his son Carl Philipp Emanuel - whereas others are simple transcriptions, like the Menuet in G major Anh 114 (track 33), which in reality was written by Johann Christoph Petzold