J. S. BACH Jonathan Berkahn - Victoria University - Victoria ...

‘Magna opera Domini’ (no.2) continually threatens to become a fugue, and the
‘Virtutem operum suorum’ (no.6) contains a good deal of incidental imitation, the only
movement properly so-called is ‘Mandavit in aeternum’ (no.10). The archaism of its
colla voce orchestration and antico texture is in keeping with the text (‘He has
commanded his covenant for ever’), but—unexpectedly perhaps—this turns out to be
one of the most original movements of the work.
The exposition is unusual, consisting as it does of a three-voice combination
from the very beginning (Ex.2.17). The core of this combination is a kind of ‘cantus
firmus’, initially a monotone (a stylised echo of Gregorian psalmody?), that descends
an entire octave step by step when the two other voices enter. The two accompanying
voices descend sequentially, passing the same motive back and forth before cadencing
as the next entry begins. Since three voices are present in even the first entry, we
might expect the movement as a whole to have a relatively massive, dense texture.
Instead, like Handel in ‘Lift up your heads’ (Messiah), Wesley exploits his five-part
SSATB texture chiefly for contrasts between higher and lower groups of voices.
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