I would like to offer a few preliminary thoughts that are foundational to the discussion regarding music and worship. In the very first place, we need to establish that music is not, itself, worship (though many seem to think so). Worship is properly the ultimate aim of everything. It is even the whole point of God’s revelation itself. Therefore, our every expression should be reflective of the person of God, particularly as He has chosen to reveal Himself in the person of Christ. My whole philosophy of music flows from this idea, both philosophically and practically.
Almost everyone who has spent any time in any church knows 1Corinthians 10:31, “Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God.” How many people have actually considered what that means? The “glory of God” is a summary statement for “all that God is.” Another way to say this is to say that the “glory of God” is the sum total of His character and attributes.
Once we accept this, we need to ask, “What does it mean to 'do everything' to the glory of God?” Many people assume that this simply means we give God the credit, and while in a tangential way this is somewhat true, it isn’t the point of the statement. In order to fully understand, it is helpful to bring another verse into the picture at this point: Romans 3:23, “For all have sinned, and come short of the glory of God.”
When I first recognized this connection, it revolutionized my whole concept of worship! Sin is failing to meet up with the standard set by the attributes and character of God (this would exclude the attributes of God’s greatness - the omni’s, etc…), and this means that God Himself is the standard. So we could also assert that all sin is ultimately a failure to properly worship God.
However, this doesn’t entirely answer the question, though it does bring us one step closer. Sin is also a failure to love, since every command by God, and especially the law of Christ, is expressed by the twin commands to love God and my neighbor as myself. Even God, Himself, is described by the statement, “God is love.”
So, to live to the glory of God is to live a life contrary to a life of sin. It is to live so that every heart response and every corresponding action in our lives is actually a reflection of the glory of God. This is, of course, impossible without the Holy Spirit’s work of regeneration (Remember the fruit of the spirit? They are all either an attribute of God or the effect of an attribute of God), and though music isn't, itself, worship. These principles certainly relate to music as a form of communication.
So a Christian can evaluate the value of any given piece of music by comparing the communication of that music with the character and attributes of God. We should be able to ask whether it reflects the love of God, the mercy of God, the justice of God, the anger of God, the righteousness of God…and so on. However, just as with the spoken word, the communicative content of the music is largely dependent upon context to accurately evaluate the meaning. This means that music must be understood in context of the musician, the venue, the occasion, and the audience.
For example, the words, "I love you" are a wonderful expression that can mean entirely different things if those words are spoken by a 4 year old to their stuffed animal, a 16 year old to his girlfriend, a wife to her newlywed husband, or an elderly husband to his dying wife. Who is speaking to whom is important, if we are going to understand the communication, and the same is true for music. Both the musician and the audience must be considered.
In addition, we can take the same words and understand them in completely different ways, depending on the venue. If it is spoken in a hospital it might communicate hope or even finality. If it is spoken in a carnival, it could be understood as a joke, or if it was spoken at home, it might communicate a close family bond.
However, not only is it important to consider the musician, the audience, and the venue, we also must consider the occasion. For example, our three words could be part of a skit at summer camp, or they could be spoken by a teenager upon receiving a new car, or they could be spoken at the end of a wedding (or funeral). In every instance, the communication is different - sometimes drastically.
Yet, we also have to consider tone of voice. If I yell angrily at my wife, “I LOVE YOU!!!” she is not likely to get the message clearly, because the emotion doesn’t match the words. Worse, she might understand exactly the opposite. The tone of voice can make these words communicate hatred, friendship, exasperation, or even genuine love. Tone can enhance or even reverse the meaning of the words.
Music works exactly the same way as language, with the added benefit (liability) that it is designed to make the emotion of our communication more evident. Think of singing as "speaking, with the volume turned up on the emotion."
This is why we cannot evaluate music by looking at its disjunctive parts, like rhythm, harmony, and melody. The communication must be viewed as a whole, considering all relevant contextual information as well as the communicative content. This is also one reason why I am opposed to the notion that there is intrinsic morality in music (independent of context).
On the other hand, I am equally opposed to those who would suggest that music is amoral and irrelevant to the communication, which would be like saying tone of voice has nothing to do with my telling my wife, "I love you." We can see and readily accept this in the realm of language, but music seems to be emotionally and practically polarizing. We really need to cut through the convoluted confusion of the "worship wars" and just get back to the point that music communicates.
Then we can move forward by observing that the communication must be Biblical (or from a Biblical perspective); it must be emotionally consistent with the verbal content (loving music goes to loving words); and it must be appropriate to the venue, occasion, and audience. Those three principles would save us all a whole lot of grief, and allow us to evaluate whether that communication properly communicates the character and attributes of God.