One of the philosophical undergirdings of the Protestant Reformation was a theory called nominalism. According to nominalism, things do not belong to kinds of things. Each individual instance is its own selfstanding kind of being. No generalizations are truly valid.
If there are no generalizations, there are no general laws.
Religious obedience, under such a schema, would be somewhat whimsical. There are no real repercussions, and no real laws. Any monarchical superior is free to impose rules, not according to natural or divine or canon law, but according to himself and his own thoughts.
Under such a schema of obedience, real or assumed, a religious subject would probably feel free to ignore the superior.
It seems to me that nominalism is a current meta-conception in Western society, and that it affects liturgical music in two ways.
First, the experience of attending Mass can be whiplashingly random. In my immediate area, even after omitting those Sunday Masses planned for special groups of Catholics--children's Masses, youth Masses, Gospel Masses, and Spanish Masses--the difference in musical styles is all over the map. Going from Mass to Mass on a Sunday is as random as opening the various doors of the theaters of a multiplex. The rules and guidelines for liturgical music over the centuries are among the most widely ignored rules in history, at last count exceeding even the blatantly disregarded laws against the rolling stop at a stop sign in Southern California.
Secondly, the vacuum formed by antinomianism--lawlessness--will not remain a vacuum. Laws will happen. Whether or not people profess nominalism, or its liturgical cousin, congregationalism, no one really, existentially, believes it. We all know we're all alike. So a "new normal" will be promoted in place of the agreed upon, long-standing norms. This "new normal" goes far beyond the sort of lazy compromises that develop inevitably over time. It's an imposed normal, a theoretically expressed normal--but one without a strong theoretical basis. It's turtles all the way down, but it is incredibly dogmatic. We all know the rules. No Latin. No Gregorian chant. No propers. No polyphony. No ad orientem posture. No solemnity in processions. No altar rails. And definitely no kneeling for Communion. Not to mention the more ephemeral, politically-generated rules. We've seen wave after wave of these temporary "new normals," usually found in the Social Concerns section of your favorite hymnal.
I think that since we're going to have rules--liturgists are involved in a public work, after all, not just deciding for themselves whether or not to personally eat gluten-free--we should dig down past the turtles and make sure we're on solid ground here. It takes no knowledge at all to simply wake up one morning, eat a good breakfast, and proclaim a new liturgical 10 commandments: Thou shalt build ugly churches, for example, or Thou shalt ignore 2 millennia of Catholic musical heritage and replace sacred music with inauthentic bluegrass. It takes a lot more study--and a lot more deep courage--for musicians, bishops, and publishers to cooperate on the all-important project of sacred music, the greatest of all the liturgical arts, and one of the vital structures of the New Evangelization.