This is such a difficult and fascinating area of the law.
On the one hand, the First Amendment protects us all from some school teacher or administrator indoctrinating our children into their favourite sect or cult ... and the majority thinks that is good. On the other hand, the First Amendments prevents the majority from imposing its dominant religious beliefs on those who do not share them ... and the majority is unnerved by this.
The area of music is especially difficult, but it is similar to many other areas where there is a literature which ought to be studied and enjoyed, but that literature contains or arises from a religious point of view. Surely students of English ought to be able to study the Canterbury Tales without their teacher being accused of a First Amendment violation. Surely students of art ought to be able to view those masterpieces which have religious subjects without their teacher being accused of proselytizing. Just as surely, there are great pieces of music which have religious content and any school system which pretended that they do not exist -- either as objects of study or pieces to perform -- would be delivering less than a complete education.
This subject seems a bit far afield from the normal discourse on this board, and I fear that we may rile up a few sensitive souls by having this conversation here, Jackie. Maybe it ought be continued by PM.
