Although you may not believe it, there are people out there who have (or had) the temerity to judge Christian Music (aka "hymnody") as being "Good," or "Bad."
First, consider the example I reproduce below, from an old Christianity Today article by E. Margaret Clarkson from ca. 1980:
Good hymns have words of beauty, dignity, reverence, and simplicity. Whether lofty exultations or simple declarations of trust, good hymns are chaste, precise, and lovely in their utterance. Their langauge is clear and concise. Such hymns are never glib or pat or extravagant or sentimental; they are always true. They speak beautifully, feelingly, compellingly, and with restraint of the things of God, and they do not transgress the limits of good taste.
Good hymns are adult in word and tone. They do not insult our intelligence by requiring us to sing immortal truths in childish or unsuitable modes of expression. They contain nothing to bewilder or embarass an unbeliever, but will speak to him of a deep, sincere, vital experience of God. While their figures of speech will have meaning for the contemporary worshiper, they will be in keeping with the worth-ship of God.
Second, check out my anti-example here: http://www.kerygmusic.com/we-are-all-together.html (I wrote this myself as an exercise, to illustrate some of the aesthetics of modern Contemporary Worship Music. No animals or guitar players were harmed in creating this example)
Note how it runs counter to the "Good hymns" practices outlined above:
- No beauty (trite chord progressions, ponderous melody line)
- No reverence (no mention of God or any eternal truths)
- Superficial, overly sentimental (an emphasis on interpersonal relationship and in-the-moment thinking)
- Childish, repetitive, simple-minded lyrics (need I say more?)
- Completely counter to the "worth-ship" of God (a hack job)
Without too much effort, I'm sure you can apply these principles to various other musics. (Yes, some of the hymns that have made it into the "canon" of Western Hymnody would be in here as well. Those seem to be the exeception, however.)