Thanks to the online discussions that have raged about the music for the papal Masses, particular the one in Washington, the Catholic differences about sacred music have hit the WaPo in a piece by Hank Stuever.
The piece isn’t bad, and depends in great part on Jeffrey Tucker of NLM  and Thomas Day, author of Why Catholics Can’t Sing as the expert voices.

There are weaknesses, however. Which are okay because it’s a complex issue and impossible to summarize in a relatively short article. Just thought I’d take the opportunity to throw some expanded thoughts out there.
First, the sides to the discussion that Stuever describes are basically the ChantHeads v. Hippies. He shows some knowledge of the Catholic musical…er…tradition of the past 40 years as he alludes to JC Superstar, “Morning Has Broken” and even notes that the music of the St. Louis Jesuits is falling out of use…
…and that’s it.
Of course, there’s much more. I’ve not heard “Hosanna, Hey-sanna” in a church setting since 1979, and I doubt you have either.
Steuver’s piece would have had much more richness in terms of that end of it if he’d explored the impact of Praise and Worship style music on Catholic liturgies and the fact that there are profound disagreements and questions about the quality and theological content of music composed after 1982. He gets a lot of mileage out of quips about guitars and nuns, but then follows that by saying you hardly see that at play anymore…which prompts the question…well, what’s the problem?
Secondly – and this is even more important.
As I’ve noted here several times, and as Jeffrey and others explain over and over again at NLM and in Sacred Music, the core issue is NOT style or taste. The CORE issue that the American Church needs to deal with (and I’d say it’s not just the American Church – this has been a worlwide failure) is the fact that when you look at the liturgical documents of the past century, which include encyclicals, motu proprios, the documents of Vatican II, as well as the liturgical books themselves, what you find there is, pretty clearly explained, an ideal.
And that ideal is not the 4-hymn sandwich. That option of “or other suitable songs” is behind Door #3 or 4, as I recall. The ideal is not a liturgy in which there’s this constant shift between talking and singing, then talking some more then singing something else in a different style.
The ideal is a unified prayer, flowing smoothly, organically, with the music fitting to the ritual, not as entertainment (a constant battle in the Church for centuries, of course) or as a nice extra, but as a form of prayer consistent with the rest of the ritual.
If you want to get an idea of what this means, think Eastern Rite and Orthododoxy. If you’ve ever been the Divine Liturgy of St. John Chrysostom or any other Eastern liturgy, you know what I mean. You get going, the chants are intoned, and you…go. It’s of a piece.
As Jeffrey wrote on NLM a while back (I couldn’t find the original at NLM, only what I’d quoted a couple of years ago)

Given all the controversy over music these days, people are often surprised to find out that the Roman Rite has an official songbook that grew up alongside the Mass. If the Lectionary is for readers, the Sacramentary is for the celebrant, the Graduale Romanum is for singers. It is the official book of music that goes with the Mass. It is what the GIRM is referring to when it speaks of chant.
The current edition of the Graduale was put out in 1974, four years after the new rite. You can buy it from most Catholic book distributors such as GIA and OCP. The gap in years between 1969/70 and 1974, which occurred because of a series of missteps, accounts for much of the current confusion over music.
In the preconciliar form, there was no question as to what the ideal was (even if it was rarely done): the Propers and Ordinary according to the Graduale Romanum. The Second Vatican Council set out to reduce the role of vernacular hymnody and increase the status of the Graduale. That is what the Constitution means by giving chant “pride of place.”

And then more recently:

It turns out that most Catholic musicians would be shocked, shocked, to know that providing music at Mass isn’t about picking and choosing. The music of the Mass is already built into the structure of the liturgy: words, music, position, place, everything. It is already there. The book in which you find this music is called the Graduale — named for the most important chant in the book, the Graduale itself, ironically replaced in most parishes after V2 with what is called the Responsorial Psalm. But just because we now sing the Responsorial Psalm doesn’t mean that the rest of the Ordinary and Propers can be tossed out. They constitute the normative music of the Roman Rite.
snip
In fact, if I were to name one single objective in Catholic music that is more important than any other, it would be simply to let people know that the Graduale Romanum exists. Truly, this is the greatest secret in Catholic liturgy today. And there is a reason for this: the very existence of the books pretty well resolves most disputes over style and disempowers those who would foist on us music that no Catholic in our history would recognize as suitable.

As I said, to picture in your mind what this means, picture an Eastern liturgy (sort of…the chant style is quite different, but the point is the organic nature of the act) or even a monastic liturgy.

This is the central issue, and recognizing this over the past couple of years (thanks to the education I receive at NLM and other places) has really opened my eyes. 

Yes, musical style is an issue, but I have real doubts as to that angle of the discussion can ever really be fruitful until people are able to look back and say, “Wow. The stuff we were singing in Catholic churches thirty years ago…we don’t sing much now. And if we did, wouldn’t most of it sound lame and dated? I wonder what the music we’re singing now will sound like in thirty more years? Hmmm…I wonder if this culture-bound mentality is really supposed to characterize Catholic liturgy? Does it really communicate what we’re doing in Mass in the most lasting, resonant, and even…accurate way? Let me think this over….”

Another key to opening ourselves to a different way of thinking on this is to start grappling with the fact that most of us think that the Mass is essentially a prayer meeting. Prayer meetings and gatherings are good, but that’s not what the Mass is. It’s something different, and exploring those differences and the assumptions we bring to Mass about what it is we’re doing there…we’re only at the very beginning of that conversation.

 By the way, if this is something that interests you, check out the new and wonderful-looking Parish Book of Chant, produced by the Sacred Music Association and distributed by Aquinas and More Books.

 A description:

It has been developed with the hope of bringing to life, in every parish and home, what the Second Vatican Council called a “treasure of inestimable value,” which is our Gregorian tradition of song.
It is compiled and expertly typeset by Richard Rice (Communio) with the assistance of the CMAA and many people involved in sacred music in the United States.
It will be available from Aquinas and More books in June 2008. You can pre-order from them right now.
Among its features:

• It contains a complete order of Mass for both the Ordinary form of the Roman Rite and the Extraordinary form, in side-by-side Latin and English. The Ordos include the sung responses of the people and celebrant. In this respect, it serves as an ideal resource for parishes that use both forms or simply hope to emphasize the relationship between them. 
• It contains a large Kyriale, which is a collection of chants that make up the “ordinary” of the Mass: Kyrie, Gloria, Credo, Sanctus, and Agnus Dei. These are the main sung parts of the Mass that are used throughout the year and the parts that all people are invited to learn and sing. This includes the four full Credos in addition to many Mass settings that have been beloved for the dominant part of Catholic history all over the world. 
• It collects 71 Latin chants, with English translations, that are for occasional use in Mass in various seasons of the year, such as hymns for Advent, Christmas, Lent, Easter, Pentecost, as well as Marian hymns and chants for funerals and other occasions. These are hymns that constitute the most serviceable of the repertory, have inspired composers for 10 centuries, and have been in the minds and hearts of Catholics for generation after generation. 
• All music is set on four-line staffs with newly typeset neumes that make the music crystal-clear for singing. The music also includes the traditional Solesmes markings to assist in rhythmic understanding and interpretation. 
• It includes a 7-page tutorial on singing chant that is invaluable for the beginner and can also teach the more advanced singer. It teaches understanding of signs, melodies, style, rhythms, and modes, all in a very brief section at the back of the book.
• Additional features include the order of service for Benediction, Gospel canticles, litanies, and Alleluias for both forms.

These features were chosen with the parish experience in mind. There is no existing resource that combines them into a single volume: the Mass, the people’s music, tutorial, and translations. Again, this is not a reprint but a newly created book that offers the core of the people’s Gregorian music. This book could be the most valuable resource yet produced to help Gregorian chant assume its “pride of place” in Catholic liturgy.

There are links to samples on the site, as well as an audio explanation of the book.