There is a very good piece by Michael Lawrence on the New Liturgical Movement Blog. Here is an extract:-
The process of learning a piece of music is an organic one, much like watching a plant grow. So, to say that only the "finished product" is capable of rendering praise to God is a bit like saying that a child cannot praise God, but his father can. Or it is like saying that the beauty of a sapling does not praise God even if the beauty of a tree does. Without saplings there would be no trees; without children, no fathers. Without the daily effort of practicing, there would be no musical performance worth listening to.
It seems to me that practicing and performance are all a part of the same work, and so the act of praise begins the moment the musical score is cracked open for the very first time. It is not the mistakes and the bumbling around that take place during the practicing that offer praise, but rather the persistent daily effort to attain the ability to sing or play a piece of music in a manner that is truly worthy of divine worship. It is an act of devotion that comes from the musician's awareness that God is deserving of the very best. Sacred music is a sacrifice of jubilation, as the Psalmist called it, and not a self-serving act of showing off.
We musicians should therefore resolve not to bury the talents we have but to nurture them each day and to keep in mind as we practice that what we are undertaking is no mundane, purely necessary task, but rather the first whisperings of the loud praise we shall later offer at the altar of God.