Friends, this link:
will take you to a nice, one-location collection of links to Vatican,
USCCB and NPM documents about Music in Catholic Liturgy.
One document with a broken link is a biggie: the US Bishops' document
Sing To The Lord from 2007
Luckily, my choir director downloaded a PDF when it was still available on the USCCB
This is information only, not meant to generate comments or discussion.