When nine-fold became six-fold . . .

[gwyn]

I'm looking at the Kyrie Cum Jubilo. Its structure is:
three-fold Kyrie in 'a', 'b', 'a' format
threefold Christe in 'a', 'b', 'a' format
three-fold Kyrie in 'a', 'b', 'a' format.

I'm wondering, when using this in the Novus Ordo, do we cut out the 'b' sections, or one of the 'a's? If the latter, then is it the first or the last in each group?

You'll know what I mean even if I don't.

[contrabordun]

As a rule, each acclamation is sung or said twice, though it may be repeated several times, by reason of the character of the various languages, as well as of the artistry of the music or of other circumstances. When the Kyrie is sung as a part of the Penitential Act, a trope may precede each acclamation.

So do it exactly as written, either as "character of the [Latin] language" or as "artistry of music" or as "other circumstance".

That's the great thing about the OF: there's a bit of flexibility

[gwyn]

Thanks Contraburdun. That's answered my question fully.

[Mithras]

We still use the Bevenot settings in Re Fa and Sol at St Peter's. They were written pre Vat 2 but make perfect sense in the Novus Ordo. I actually wrote a ninefold Kyrie a few years ago for a celebration of the Extraordinary Rite but have no problems using it in the new rite. When I use de Angelis or Cum Jubilo however, I tend to go fort sixfold - in this case the last Kyrie always has the slightly extended setting.