Verse 2 and verse 3 of the sequence Veni sancte spiritus (Cantus ID ah54153) quoted in T1 and T2 alternatively (passage "Virgo carens simili ... possimus in gloria"):
1--h--k--l--l--kj--k--l---kj--h--kj--g--fe--d--dc----g--f--gh--f--ed--c--d----4
"Consolator optime / dulcis hospes anime / dulce refrigerium." (http://manuscrit.ville-laon.fr/_app/visualisation.php?cote=Ms263&vue=192) See MACEY 1996, 170-171.
1--l--l--kj---k--lk--j--h---f--ed--c--de--f--g--f----g--h--ij--h--g--f--ed---d---4
"O lux beatissima / reple cordis intima / tuorum fidelium" (http://manuscrit.ville-laon.fr/_app/visualisation.php?cote=Ms263&vue=192)
Seemingly presented as a two-part motet on two openings in I-Mfd 1 (with “verte cito” and “custodes”).