alleluia alleluia (dominus) regnavit

Several elements contribute in making this chant particularly hard to assess:

• the Ad laudes rubric preceding it, even though only three antiphons are provided before (thus this item should expectably mark the beginning of 2^nd Nocturne, not Lauds, in case the first three antiphons mark the beginning of Matins); 
• its text only being found as is in the genre of Laudes in the Old Hispanic rite—clearly not fitting this document; 
• its musical incipit apparently pertaining to a second mode antiphon intonation;
• the cantillation on last word written iubilate not providing under any circumstance an end to the piece (this last detail makes it possible that, whatever its nature, the entire piece was not reported in full).

Concluding, I tag the piece under the liturgical occasion of Lauds and the genre of Antiphon, only with much uncertainity.