Thorny subject, Carlos!
I see a few B-flat
ficta possibilities: (1) the descending B's in T1.m4 & T2.m5; (2) descending B's in T1.m11 & T2.m12 - this second possibility being more critical in that (with B-natural) they resolve an imperfect minor third to a perfect fifth, which by the attraction principle would ask us to alter the minor third to a major third by raising the B-natural to a B-flat).
By the same principle, it would appear that some F's should be raised to F-sharps: (1) T1.m5 (attraction principle, cadence) & T2.m6 (if only to preserve the exactness of the canon); (2) most (if not all) the F's from T1.m26 & T2.m27 to the end (attaction principle & cadence or leading tone). Rather dubious (to me) would be raising the F's to F-sharps in T1.m19 & T2.m20 (leading tone, and imperfect/perfect resolution via attraction principle in T1).
Here I've only considered
ficta that would be applied to both voices of the canon, preserving its exactness. If this exactness is relaxed, then someone taking these ideas to extremes might argue for a C-sharp in T2.m4 (but not in T1.m3 which would result in a tritone) - but this is best avoided since there is no cadence to deal with. It's probably better to reject these outright, since then one is beginning seriously to tamper with the modality of the piece. Adding
ficta here and there where the result stretches the (supposed) rules or simply because it sounds "better" to us (more than four centuries after the fact) is not such a good idea.
I've stressed and agonized several times over issues of
musica ficta. Compare, for example, the different treatments of (essentially the same underlying music) Gombert's
Je prens congie and
prima pars of
Lugebat David Absolon (especially from m.103 to the end). Or Crecquillon's
Dont vient cela with and
without ficta.
What would I do with the Brumel
Benedictus? ... probably insert the B-flats of instance (2) m.10/11, as well as the F-sharps of instance (1) m.5/6 and some those in instance (2) m.26/27, m.28/(29?), m.(30?)/31, m.32/33. And, as always,
musica ficta inserted by modern editors (especially) me are
suggested possibilities ... it's up to the performer to decide whether to accept them.
By the way, the article/dissertation by Vincent Arlettaz is quite good - well researched and even-handed. There is an
online summary at his website.
Chuck
Charles H. Giffen
CPDL Board of Directors Chair
Admin at & Manager of ChoralWiki