With the Fantasia Chromatica
we are immediately plunged into the tangy world of mean-tone temperament. It is not possible to summarise such a complex subject in a few sentences, but because of the distinction between diatonic and chromatic semitones – e.g. the diatonic semitone D-E flat is smaller than the chromatic D-D sharp – certain notes which in modern equal temperament share the same key on the keyboard, cannot sound equally well in both flat and sharp keys. So, whereas on a modern keyboard they are the same note, in mean-tone temperament D sharp is higher than E flat. (Other enharmonic convergences do not matter because the notes D flat, G flat, A flat and A sharp were hardly, if ever, used.) Sweelinck’s Chromatic Fantasia
– based on a theme typical of all such works, filling the space between a perfect fourth, here moving down from D to A – is one of the first works to use both D sharp and E flat in the same piece; only William Byrd had done so before. The device of using a split key in order to provide both notes, as on the organ which Christopher Herrick plays, is known to have existed in certain organs of Sweelinck’s time. As with the other longer imitative pieces on these discs the composer displays both enormous command of contrapuntal technique and a sure grasp of large-scale form. Sweelinck’s biographer, Frits Noske, has identified a tri-partite structure to these works although, as he says, this is more evident to the eye than the ear. The first section takes up roughly the first half, in which the theme is combined first with one counter-subject and then its inversion. Brief periods when the main subject is absent give the ear respite from the chromaticism. In the second section the theme is presented in augmentation or double length notes, and then in the final part in diminution, speeded up first to twice its original pace and finally to four times. Brilliant toccata-like flourishes bring the work to a dazzling conclusion.
from notes by Stephen Westrop © 2003