| Prolongation,
Auskomponierung. The extension (composing-out) of an underlying
note, interval, or harmony (Stufe)
by the introduction of additional notes at higher structural
levels. The progressions of the middleground
prolong the background, and the detail
of the foreground serves to prolong the
middleground. Prolongation may be contrasted
in general terms with progression: prolongation represents the retention
of a given sonority, whereas progression suggests a motion from one
state to another. In general, progressions serve to prolong deeper
levels. The example, from Variation 18, shows a prolongation of the dominant harmony and of the 5 as the main upper voice note. The prolongation is carried out through linear progressions, a fourth, C-F in the upper voice, and a third, A-F in the lower part. The working out of this contrapuntal framework in a chromatic manner leads to the augmented-sixth chord at the end of m. 6. |
