This involves two separate questions, both of which I will try to answer. One is what are the rules on recitation of the Gloria and Credo after the change of rankings in the calendar from the "Duplex" "Totum Duplex" "Simplex" etc. system to that of first-, second-, third-, etc., class feasts. These rules are basically unchanged from before 1960; so one needs only to have a current Dominican Rite calendar to apply them. The current year's calendar can be downloaded at my Dominican Liturgy blog.
The next issue is what Dominican chant ordinary is to be used with the various feasts. This is more diffciult because the reassignment of the various Ordinaries of the Dominican Kyriale are not easily available, unless you have a copy of the 1965 Dominican Rite Missal, which gives the reassigned Masses by the intonations of their Glorias. I give those below. Here is a summary of the rubrics and ordinaries. to be used.
1st-class Feasts:
Gloria and Credo are both always said
Mass Ordinary I. "In Festis solemnibus" Graduale S.O.P., p. 126*ff
Except when it is a feast of the Blessed Virgin, then:
Mass Ordinary V. "Sabbatis, Festis, et Octavis B.M.V." GSOP, p. 139*ff
All Sundays of the Year except Easter and Pentecost
Credo is always said, Gloria is said outside of Advent, Lent, and Passiontide.
Mass Ordinary II. "In Duplicibus communibus et Dominicis majoribus" GSOP p. 132*ff
2d-class feasts of Apostles:
Gloria and Credo are both always said
Mass Ordinary III. "In Duplicibus et Dominicis minoribus" GSOP, p.135*ff
2d-class feasts of the Blessed Virgin Mary:
Gloria and Credo are both always said
Mass Ordinary V. "Sabbatis, Festis, et Octavis B.M.V." GSOP, p. 139*ff
All other 2d-class feasts:
Gloria is said but not the Credo
Mass Ordinary III. "In Duplicibus et Dominicis minoribus" p.135*ff
Note that during Paschal Time on 1st- and 2nd-class feasts the Easter
Kyrie is used from Mass Ordinary IV. "Tempore Paschali" p.138*
3d.- and 4th-class feasts of BVM (i.e. Votive on Saturday):
Gloria is always said, but not the Credo
Mass Ordinary V. "Sabbatis, Festis, et Octavis B.M.V." GSOP, p. 139*ff
All other 3d-class feasts:
Gloria is said but not the Credo
Mass Ordinary VI. "In Semiduplicibus et Simplicibus" GSOP p.143*ff
All other 4th-class ferials and all days of penance (i.e. Ember Days or Vigils)
Gloria and Credo are never said
Mass Ordinary VI. "Profestis diebus" GSOP p.145*
Note the "Benedicamus Domino" is now only used when some function IMMEDIATELY follows the Mass---e.g. Procession on Holy Thursday---see 1965 Missal. The Ite missa est for ferials is found in the 1965 Missal, not in the Graduale.
Other Mass Ordinaries may, of course, be substituted for the Dominican Cycle, and (Roman) options are given in the supplement to the Kyriale in the Dominican Gradual.
