Look at this window: it is nothing but a hole in the wall, but because of it the whole room is full of light. So when the faculties are empty, the heart is full of light. Being full of light it becomes an influence by which others are secretly transformed.
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.