The Praeludium in D major, BuxWV139 opens with a twenty-bar introduction whose extemporary style might suggest an organist exploring an unfamiliar instrument before settling to his task. There follows a four-voice fugue on a subject in which a repeated note prominently features; a sustained passage in which Buxtehude demonstrates a knowledge of complex harmony; and the lively, toccata-like section (interrupted by another sustained passage) with which the piece concludes. Thus ‘prelude and fugue’, the phrase commonly used to describe such works by Buxtehude, is not entirely apt, for instead of a clear-cut division into two substantial movements of more or less equal length, there is a succession of relatively short passages, strict fugal writing alternating with sections of an improvisatory character, some of them lively and harmonically straightforward, some stately and harmonically complex.
from notes by Relf Clark © 2008
