I am starting this section in response to some questions floating around both here in Springfield and in other areas around the State and the Country.
The question is asked: What of the Ordinary of the Mass (Kyrie, Gloria, Creed,etc), must all the parts come from the same Mass setting whether in the Liber, Kyriale, or the work of some composer?
The answer is a resounding NO! You may use the Kyrie from Mass VIII, Gloria from Mass IX, Credo V, Sanctus from Byrd's Mass of Three Voices, and the Agnus Dei from Palestrina's Missa Papa Marcelli. The Gregorian Mass settings in the Liber Usualis are suggestions, they are not binding.
In Springfield, we have High Mass once a month and the choir knows Mass VIII. It will debut Mass XVII shortly for Gaudete Sunday, and then begin incorporating Mass XI into its cycle. It is wise to have at least a few of the Gregorian settings of the Mass known by the Choir. In my opinion, Masses VIII, IX, XI, and XVII are most appropriate if the choir is not professional, or does not meet regularly. It goes without mentioning of course, that the Funeral Mass should be learned.
While this concludes the first "Ask a Trad!" post, I am hoping that in the future we will receive email questions regarding rubrics for beyond the Communion Rail or guidelines for the choir. Any emails sent in this regard will be posted unless the questioner states that he prefer otherwise. God Bless!