Drei Préludes, Prélude I

These three Préludes are written for the Clavemusicum omnitonum in 31-meantone temperament, which allows septimal intervals to be treated as enharmonically equivalent to familiar chromatic ones (e.g., the harmonic seventh as an enharmonic equivalent of the augmented sixth, and the septimal major third 9:7 as an enharmonic equivalent of the diminished fourth). The harmonic language could be thus regarded as a kind of septimal „hypertonality“.

No. 1 highlights the »wolf fifth«, which is smoothly integrated into the world of septimal harmony through its enharmonic equivalence with the septimal fourth (21:16). It furthermore forms a perfect (meantone) fourth with the just seventh in a 7/4-chord, which is (in 5-limit) a characteristic and particularly beautiful sonority of French baroque harmony.

No. 2 explores the enharmonic equivalence of the diminished fourth and the septimal major third and introduces „Bachish" progressions of diminished seventh chords, which in meantone temperament results in distinct sonorities for each inversion.

No. 3 makes use of further foreign intervals with a certain „mystic“ quality, such as the double-diminished fourth, which lies between the minor and major third and can also be seen as a secondary septimal interval, being the distance between a just seventh and a diminished fifth or a minor ninth, respectively.