Bibliotheca Arnamagnæana - 01.06.1968, Page 170
IN PENTECOSTE
pro- pi- ti- ua aan- cte spl-ri-tua. Tu qul , J 0- mni-um . J -i-
—p—i—p—j—p f f- r r-l1 f 1 1—1—1—
la-ctantum pro chri-sto cer-ta- mi-na. Cl-ves an- ge- li-ci y
quem cre-a- sti frau-de sub- do-la. San-gui-ne pro-prl- o
As we see, not all the fourths are perfect; F—b makes a tritonus.
And when the melody moves in leaps of two minor thirds in suc-
cession — as it does on “exaudi”: b—d—/ (and in reverse order in
v. 13: “-riosum”) — the distance between the first and last note is
an imperfect fifth, which was forbidden in Gregorian chant, and
rings rather modern.
Another consequence of the transposition is that the mode changes
from Mixolydian (with final G) to Ionian (c), which was also for-
bidden in the strict ecclesiastical song.
But the purpose of the transposition evidently was just to obtain
a leading note a semitone beneath the final; and as F sharp did not
enter into the system of notation, the desired result was obtained
through the cadence b—c, which the transposition provided.
Very interesting is Y, which sets the melody of v. 11 not a fourth,
but a fifth higher than “Celsa pueri” and “Rex omnipotens”. Thus
instead of the imperfect fifth b—(d)—/ in the melody of “exaudi”,
we get the perfect fifth c—(e)—g, and the cadence becomes c—d,
which is a normal one to alternate with F—G. But from v. 12 on,
the transposition here also is a fourth up.
It is remarkable that K in vv. 12 and 13 has b flat (whether it
had it in v. 11 too, is unknown, but it is not unlikely). The result
is that the cadences become b flat, c, viz. Mixolydian mode trans-
posed to c. This has perhaps come as an emendation from the illicit
Ionian mode.
But vv. 1-10 are actually in the Mixolydian mode, with final G;
to preserve the mode, one had therefore only to forbear the trans-
position, such as was the case with the form of the melody used by
“Celsa pueri” and “Rex omnipotens”, and by all except one (Sårum)
of the 15 MSS. of “Sancti spiritus” collated in Moberg, and also
by our Icelandic MS. It is very significant that all three Norwegian
MSS. of “Sancti spiritus” follow the exceptional English form in
transposing the melody of vv. 11 ff. a fourth upwards.
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