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48 BACH / ISOIR_TRANSCRIPTIONS
The famous chorale
Wachet auf, ruft uns die Stimme
BWV 645 opens the set of six
titles in the Schübler anthology. The original vocal setting, the fourth number of
the cantata of the same name, BWV 140, places the melody in the tenor, with an
accompanying ritornello on the strings, in the style of an ariawith solo instrument.
Bach’s organ transcription remains faithful to this layout, and Isoir does not diverge
from it. Nevertheless, he extrapolates from it a continuo realisationwhose subtlety
and discretion should not be allowed to obscure the ambition and elevated nature
of its inspiration. Here is no automatism in the figured bass, no mere harmonic
filling, but a genuine contrapuntal discourse that accompanies and dovetails with
the existing work.
Yet it would be restrictive to dwell only on the sonic appeal of the device without
pointing out how it acts, in this ‘concertante’ chorale, to reveal the multiple
dimensionstraversedbyBach’smusic.Makingnodistinctionbetweeninstrumental
and vocal, secular and sacred, transposed from one universe to the other without
any modification of the musical idea, making use of the concerto in the Collegium
Musicum as in church according to the appointed custom, it is free of all rigidity.