My old friend now-Archbishop Alex Sample, before his translation to Portland, issued a Pastoral Letter on Sacred Music for the Diocese of Marquette. It is called “Rejoice in the Lord” and it is a hit.
First, remember his spectacular sermon about the older form of Holy Mass? HERE. Sample is the real deal.
Find the pastoral letter HERE.
Here are some samples (sorry!) from the letter:
This is an important discussion to have, since so often the music selected for Mass is reduced to a matter of subjective “taste,” i.e. what style of music appeals to this or that person or group, as if there were no objective principles to be followed. There are indeed objective principles worthy of study and proper implementation, as will be shown.
Church teaching emphasizes that the music proper to the Sacred Liturgy possesses three qualities: sanctity, beauty, and universality. Only music which possesses all three of these qualities is worthy of the Mass.
Finally, the third essential quality of sacred music must be considered, i.e. its universality. This quality means that any composition of sacred music, even one which reflects the unique culture of a particular region, would still be easily recognized as having a sacred character. The quality of holiness, in other words, is a universal principle that transcends culture.
[... I think you can see where this is going ...]
Any discussion of the different forms of sacred music must start with Gregorian chant.
Given all of this strong teaching from the Popes, the Second Vatican Council, and the U.S. Bishops, how is it that this ideal concerning Gregorian chant has not been realized in the Church? Far from enjoying a “pride of place” in the Church’s sacred liturgy, one rarely if ever hears Gregorian chant.
This is a situation which must be rectified. It will require great effort and serious catechesis for the clergy and faithful, but Gregorian chant must be introduced more widely as a normal part of the Mass. Some practical steps toward this are outlined in the Directive section of this pastoral letter.
[... OORAH! ...]
The Church recognizes an objective difference between sacred music and secular music. Despite the Church’s norms, the idea persists among some that the lyrics alone determine whether a song is sacred or secular, while the music is exempt from any liturgical criteria and may be of any style. This erroneous idea, which was alluded to earlier, is not supported by the Church’s norms either before or since the Second Vatican Council.
Hymns are a musical form pertaining more properly to the Liturgy of the Hours, rather than the Mass. Hymn-singing at Mass originated in the custom of the people singing vernacular devotional hymns at Low Mass during the celebrant’s silent recitation of the Latin prayers. However, the current Missal as well as official liturgical documents envision a singing of the Mass as outlined above. [You'll have to go read that part on your own. You won't be wasting your time.]
The texts of the Roman Missal and the Lectionary, and none others, constitute the official Mass in English. No one in the diocese, including the Bishop, has the authority to add to, subtract from or change the words of the Mass, either sung or recited. The only exceptions are when the Missal specifically gives an option, using expressions such as “in these or similar words.” This is to be strictly interpreted and observed.
Then there are norms.
Have a look at the letter and then reflect on what you experience in your parish.