We use objective criteria for selecting congregational songs at SGC (you can't evaluate all musical styles or settings with the same criteria in every country).
They are:

1. "Sing-ability": specifically, the range, tessitura, rhythm, form, harmonic structure, melody, and style should be familiar and accessible to a person with little or no musical background so that they are able to learn and sing songs reasonably well after one or two attempts.
2. Text: Must be biblically true. Must teach the theology that we at SGC believes and teaches. Must honor Christ. The body of songs we use will reflect the full attributes of God. The words will match the music fairly well.
3. Musical style: Songs will usually be familiar to the majority in our congregation. Most congregational songs should not be longer than 4 minutes and be written so that they can be memorized.

Subjective criteria: Opinion based.

1. Familiarity; "I grew up singing this, so it must be good."
2. Age of music; older music is better OR newer music is better.
3. Style of music; traditional hymns are better than contemporary music or vice versa.

Based on objective criteria, music is not neutral. But we have to carefully evaluate music using only objective criteria and not let our own subjective criteria enter into our judgment.

There is a missional implication for all this that is important to remember. What is worldly to one person is not to another. For instance, Newton objected to Handel's Messiah being sung in church because he thought the music too worldly. Music is an art form, not an exact science. Thus, its very nature is subjective because it's worth cannot be proven by all people in all cultures over time. Music is constantly changing, mostly due to culture. I don't believe culture should totally dictate what we use in church, but we cannot deny or escape it. The music we currently use was primarily shaped by culture. All musical styles have "baggage".

"Performing" criteria

1. The leadership voices should be heard above the accompaniment by the congregation. The purpose of the instruments is to support the primary instruments, which are the voices of the congregation.
2. The leaders should not distract the congregation with excessive movements.
3. The total volume should not be so loud so that the congregation cannot hear themselves singing.
4. The over-all atmosphere created by lighting and sound should not give the impression of a "performance" by the worship leaders.