A few years ago as a parish Music Director, I founded a choir for young people. I did it wrong. As a big fan of William Byrd's Mass in Three Voices, I thought we could start with the Kyrie of that Mass. This was a big mistake. I had four dedicated and talented kids, a nifty name, "The Youth Classical Schola," a piano, and sheet music, and we were never able to learn much of this piece, unfortunately.
We took some time off because a) it wasn't working well, and b) Holy Week was swiftly approaching and I had to focus on the parish's immediate liturgical needs.
Then came Pentecost. I had planned to sing the Introit text to a Psalm tone melody. I ran into one of the original Schola members and taught him to sing the Introit in a few minutes. He took my place, did very well, and immediately changed the focus of the Schola from polyphony to chant. This was the right way to go. We bought a stack of PBCs, downloaded some of Fr. Weber's English propers, and were on our way. This is from the second year of their singing, the Communion Antiphon for All Saint's Day.
At the same time, I was leading the parish's Adult Choir towards polyphony, but by another route. Since they are good sight- and part-singers, and knew some 19th century motets, we went backwards historically by stages, especially oratory, until we were able to master pieces by Victoria and Byrd.
It hasn't always been smooth sailing. Over the years the Schola has had its ups and downs, as parish needs and perceptions have shifted. Anyone who has done anything like this knows that there will be some in the parish who will object to sacred music on grounds having to do with "the spirit of Vatican II." (I believe that many people in all honesty truly believe that the Council outlawed both Latin and chant--although in fact the opposite is true.) But also, any parish has real needs that a DM's limited perspective might not appreciate--one of the many reasons I am convinced that the Pastor of a parish must always have the final say in any ministerial decisions. The Pastor in a parish reflects the threefold munera of Christ, priest, prophet and king. He is responsible for sanctifying, teaching and governing the parish, and being on a parish staff means accepting that the ultimate responsibility for all areas is the Pastor's.
Over the long haul I believe this approach has been a success. About a hundred young people have been in and out of the Schola over the years, each one of them staying at least long enough to learn a little Latin and their Salve Regina, to have the experience of praying and singing in a group, and to learn an Ordinary or two. Most have stayed longer and learned more, including four of the five sequences. They have sung at many Masses, including two sung parish Masses in the Extraordinary Form. Note that this is not a school group, but a parish group. It is completely voluntary.
One sterling moment was the invitation the Schola received from the organizers to sing at the first Pontifical High Mass held in the Upper Church of the National Shrine of the Immaculate Conception in decades. They chanted during the vesting, along with a school choir that several of the young people helped train.
Since I left the parish last September, the responsibility for continuing the singing has been up to the young people themselves, and after singing chant for years, they were ready for polyphony. They are making their way through a booklet I made for them, sampling the 5 polyphony masters I wanted them to experience first: Lassus, Tallis, Palestrina, Byrd, and Victoria. A young organ student of mine, a remarkable musical prodigy, teaches, conducts, and sings bass. A core group of four very talented young ladies from a single family sing in the other parts, holding the group together. Other advanced choristers, as young as ten years old, fill out the ranks.
I have just heard that they have learned the Kyrie from Byrd's Mass in Three Voices.
The expenditure of parish resources for this project has been extremely limited. Except in the case of extraordinarily special events, I spent a total of 5 hours a week with these young people at most, and that was during the period when we sang at a weekly parish Mass. More often, my time was 3 hours per week. Now they sing by themselves. It is a small expenditure and a huge payoff. An hour a week would not be too little to make a good beginning.
I firmly believe that every parish can and ought to make the effort to begin a chant schola for children.