One of the worst results of the liturgical destruction that was the result of Vatican II and post council committees was the loss to 2-3 generations of the richness of the liturgical life and the mass that had lasted for centuries. The reality is the council called for Latin to maintain it's pride of place and Gregorian chant was to remain the preferred music along with some polyphony. You will meet those that will tell you to your face and believe that "Vatican II did away with Latin". For children, it too often ended up meaning the loss of the chants that were known by all (Ave Maria, Salve Regina) as well as the loss of learning the richness of chants in their Catholic Schools. The Catholic experience was then and remains varied, but I have spoken with enough people and seen their accounts to know that there were many children who learned the ordinary chants for the mass and the propers. There were schools and churches where the oldest students, the 7th and 8th graders, who were the most accomplished were called upon to sing for funerals and other special services.
Pope Paul VI, alarmed at the wholesale abandonment of chant by the mid 1970's promulgated a collection of chants that he said all of the faithful should know. It was called Jubilate Deo and I actually have a booklet and cassette tape (dating myself) of the collection. This is significant. The pope who oversaw the end of Vatican II and the changes was indicating things had gone too far.
What we got in America, was at too many parishes guitar based pop music. There are parishes where I have seen the drum kits on the altar since new churches are not built with choir lofts. I have some guilty pleasures- one of them is some not so great 70's pop. If I channel hop and "Seasons in the Son" or "Baker Street" or even Bay City Rollers comes on I will likely listen. "Peace Train" is on my Ipod. When it comes to the music in the Holy Sacrifice of the Mass, top 40 should not be part of the equation. When people try to change the Holy Mass into just a meal and a love feast around the table (a protestant idea), problems arise.
So instead of learning the chants which elevate mind, body and spirit and that are not hard to learn (a pre-school child literally can pick up some chants) children's masses are generally plagued with bad music or pop based tunes better saved for a prayer meeting or other casual gathering.
The majority of children graduate from Catholic grade school without knowing the basic chants unless they learn them some other way. That is a crime and a neglect of our children which has and is depriving them of their religious heritage.