As a pastor, who loves music and hates most "Christian music," I’ve been pondering this question for some time and thought that I had already cycled through all of the explanations. But Matis’ answer was stated more succinctly than I’ve been able to—shamefully so since it turned out to be the explanation that should come most quickly to a Lutheran. He said, “I let the music be the holy thing.”
For most Christian artists, the music is not the holy thing itself. It is only a tool we use to point to some grander doctrine or idea of the divine. After all, wouldn’t it be idolatrous to make a holy thing of something as palpable and finite as a song? At first glance, this all sounds very pious and right-headed (and weary churchgoers like myself might swear that many praise songs have attempted to solve this problem by simply not being finite).