There's one bit I disagree with:
Make sure you have the best musicians you can find (paid or volunteer) and use them; do the difficult things and ask people who are holding your program down or even making it worse to step aside."Best" is a subjective term - and often the best of musicians want to make great music, rather than to model God's love for their colleagues and parishioners. I'd rather have a teachable musician with a heart to serve God's people, than a virtuoso any day.
But one of their key points is
It’s not exactly clear to us why that is so, but congregational singing seems to be a reliable bellwether for church health.Like them, I believe this is true, even though I have no evidence, and no real explanation about why it's the case.
Then, today, I was totally stunned to find this gem in a Catholic hymn book published in Australia in 1952 - long before Vatican II was called. I've included a picture of the key bit here - just because it's so stunningly different from what many traditionalist musicians would have us believe about church music pre VII, and the expectations about who (people vs choir) should be singing.
You can read the whole thing here: http://nla.gov.au/nla.mus-vn2152603-s4