The large-scale Fantasia (a-Phrygian)
on an even more impressive scale than the Fantasia Chromatica
, uses a pre-existing theme from a lute fantasia by one Gregorius Huwet, which had appeared in Antwerp towards the end of the 16th century. Although this theme contains the notes B flat, A, C and B natural, which in German notation spell Bach’s name, this can be nothing but a coincidence, and once the piece is underway it cannot be heard as a motif of significance. The three sections are more easily distinguished here because the points where the theme is presented first in augmentation and then diminution are marked by a reduction to a two-part texture. The theme is treated here as a cantus firmus, in the manner of variation technique. The contrapuntal working is, if anything, even richer, with a greater abundance of counter-subjects.
from notes by Stephen Westrop © 2003