You can find in the instruction from 1958 entitled "Musica Sacra et Sacra Liturgia" the following point (here it is in English):

14. a) In sung Masses only Latin is to be used. This applies not only to the celebrant, and his ministers, but also to the choir or congregation.
"However, popular vernacular hymns may be sung at the solemn Eucharistic Sacrifice (sung Masses), after the liturgical texts have been sung in Latin, in those places where such a centenary or immemorial custom has obtained. Local ordinaries may permit the continuation of this custom 'if they judge that it cannot prudently be discontinued because of the circumstances of the locality or the people' (cf. canon 5)" (Musicæ sacræ disciplina: AAS 48 [1956] 16-17).

In my church quite often after singing Offertory and Communion Antiphons we add some fitting vernacular hymns during celebrations of the EF Masses. Elder people say that before the liturgical reform (in fifties) this custom was quite usual in Poland.

In our diocese, this instruction has been interpreted to mean that, because there are no celebrations of the EF which have celebrated a 'centenary' in unbroken succession, nor an 'immemorial custom', we do not sing vernacular works of any sort between the Asperges/Prayers at the Foot of the Altar and the Last Gospel. However, we do sing vernacular hymns for the entrance procession (i.e., before the Asperges) and for the recessional as both of these are technically 'outside' of Mass. I appreciate this common-sense and obedient interpretation.

I am just old enough to remember the EF from my childhood, but not old enough to remember details such as whether or not the ethnic parishes of Philadelphia in which we had extended family sang in the vernacular or not and when exactly that might have occurred.

The "latin only" clause is one that traditionally has never been followed, and not just in the last 100 years, especially by certain national groups, but also by ordinary parishes here in the US. In regards rubrics, it is certainly low on the list those which belong to a 'hierarchy of assent', and this is evidenced by even the SSPX in France and elsewhere. At St Stephen the First Martyr, Sacramento, CA, which is most certainly the parish in question, we use english regularly, generally at communion. We do not use hymns except at the end of the High Mass and occasionally for the procession at the beginning of Mass before the Asperges. The english we use during the Mass would fall into the category of "motets/anthems"- so that pieces like "Verily, Verily I Say unto You" and "If Ye Love Me" belong to our repertoire along with latin repertoire of every age. It was reasoned by one of our more rubrically minded priests of the Fraternity of St Peter, the man who founded St STephen's and now the Superior General of the FSSP, that the traditional way of looking at communion of the faithful is that it is not technically part of the Mass (hence the traditional 2nd confiteor), and therefore would not fall under the latin only clause. For me however, it has always been enough to look at the practice both in this country and abroad, especially of those groups that have used the EF continuously. A parish situation it is different than a chaplaincy at a college or university perhaps, but in a parish that uses exclusively the Extraordinary Form, it is important to avoid the "museum like" quality of the EF that is so easily brought about by singing nothing but 16th century polyphony for example. At St Stephen's, Lauridsen, Poulenc, Howells, Britten and others in latin and english (or french or german for that matter) find a comfortable home along the likes of Victoria, Palestrina, Byrd, Machaut and Mouton. We have found a happy balance at St Stephen's which might not suit everyone, but seems to suit us quite well.

[quote]It was reasoned by one of our more rubrically minded priests of the Fraternity of St Peter, the man who founded St STephen's and now the Superior General of the FSSP, that the traditional way of looking at communion of the faithful is that it is not technically part of the Mass (hence the traditional 2nd confiteor), and therefore would not fall under the latin only clause.[/quote]

An FSSP priest I work with related this interpretation to me recently. And while I don't share Jeffrey Tucker's exact opinion on this, I don't think it would pastorally wise to sing English Motets during a sung mass for a well established community.

My experience is that most TLM community folks are more open to things than is generally thought. It is the vocal minority that gets all the attention. It is not helpful to stereotype an entire group of people as trying to regenerate a culture by reading documents. Most TLM folks are just trying to raise their children in a genuinely Catholic environment and that is the best place to do it.

There is also a lot of confusion as to what the rules are and people are doing their best. I think a modern TLM music rule list from Rome would be helpful rather than trying to dig through 50 or 100 year old documents and making up rules as go along.

The "latin only" clause is one that traditionally has never been followed, and not just in the last 100 years, especially by certain national groups, but also by ordinary parishes here in the US.

*Cough*

It was followed in every Parish in Milwaukee--at least those which paid attention to the local Ordinary's music/liturgy master, Rev. Elmer Pfeil. And that was most parishes.

YMMV, of course.

the suggestion that "it is not technically part of the Mass" is rather an extravagant opinion.

Lawyers would use the word "extraordinary."
They mean it differently than we do.

Thanks, everyone, for the interesting comments.

It does seem appropriate to allow local custom to have some influence, but as we know, custom has been a source of many evils, as well -- evils that the Liturgical Movement was trying, in its better days, to overcome. Moreover, it is all too easy to fall into an almost Protestant "pick and choose" attitude about church documents that were intended to provide clear guidelines for liturgical praxis. I admit that sometimes the documents do not always seem to harmonize perfectly and the chaos of the past fifty years has left many people scratching their heads about how to move forward with the EF, but still, the Vatican does not issue regulations just for fun; they are meant to be implemented with tranquil acquiescence. A sane and sincere adherence to rubrics and norms is the baseline for all Catholics.

While I would not reject the singing of English hymns or motets in principle, it is not at all clear to me that the still-valid regulations for the EF can be understood to permit vernacular music during a High Mass (i.e., once it has begun and prior to its completion). The opinion of the FSSP priest on the communion of the faithful sounds like a bit of a stretch, but only the Pontifical Commission Ecclesia Dei, or perhaps the CDWDS would be able to clarify that point officially. And, in keeping with what I've said, if the clarification was in favor of vernacular pieces, then I would certainly accept that position!

Anyway, thank you all for your input.