Only the Spirit of the Holy One can impart to the human spirit the knowledge of the holy. Yet as electric power flows only through a conductor, so the Spirit flows through Truth and must find some measure of Truth in the mind before It can illuminate the heart. Faith wakes at the voice of truth but responds to no other sound... Still, there must be humble penitence in the heart before Truth can produce faith.
To listen to music or to sing a chant is to do something that has no practical purpose; it is just celebration and praise; it is just tasting the joy and beauty of life, the glory of God. Listening to it, even in the midst of a very purposeful day, reminds us to add the other dimension to our experience, the dimension of meaning, that makes it all worthwhile.