I think that a song, when it works, never mind a piece of long form music, even a song is something that speaks to itself but has a language all of its own, ideally.
To give real service you must add something which cannot be bought or measured with money, and that is sincerity and integrity.
Parochial schools in the United States are also responsible for educating students from a wide range of ethnic backgrounds, including many who are non-Catholic.