As someone who is proudly Lutheran, it's not a secret that I have an appreciation for the teaching of Martin Luther. In church history, there are many great theologions like Luther or Calvin that have shaped the church that we see today and a lot of times many of their insights have a lot of value for us today. Martin Luther wrote the following regarding music:
I, Doctor Martin Luther, wish all lovers of the unshackled art of music grace and peace from God the Father and from our Lord Jesus Christ! I truly desire that all Christians would love and regard as worthy the lovely gift of music, which is a precious, worthy, and costly treasure given to mankind by God. The riches of music are so excellent and so precious that words fail me whenever I attempt to discuss and describe them....
It's not very often when I think about Luther, especially considering the theological library that he created, that I think of him as an artist. But Luther was an artist, a musician, writing songs that for hundreds of years would be passionately sung by worshippers in their congregations. I can just imagine the passion as Luther wrote these words; I think of the young worship leaders in our generation, passionately desiring that everyone will connect with this gift of music that God has given. And not only is that desire prevalent, but how often do these same passionate artists resonate with Luther, feeling that "words fail [them]" whenever they try to describe the gift of music.
In summa, next to the Word of God, the noble art of music is the greatest treasure in the world. It controls our thoughts, minds, hearts, and spirits.... Our dear fathers and prophets did not desire without reason that music be always used in the churches. Hence, we have so many songs and psalms. This precious gift has been given to man alone that he might thereby remind himself that God has created man for the express purpose of praising and extolling God.
In proper Luther fashion, it is pointed out that the art of music serves the Word and not the other way around. Don't screw that up. We must be careful that we do not start worshipping music and forsake worshipping Christ. Luther also seems to have no problem celebrating the emotions that are stirred by music.
However, when man's natural musical ability is whetted and polished to the extent that it becomes an art, then do we note with great surprise the great and perfect wisdom of God in music, which is, after all, His product and His gift; we marvel when we hear music in which one voice sings a simple melody, while three, four, or five other voices play and trip lustily around the voice that sings its simple melody and adorn this simple melody wonderfully with artistic musical effects, thus reminding us of a heavenly dance, where all meet in a spirit of friendliness, caress and embrace. A person who gives this some thought and yet does not regard music as a marvelous creation of God, must be a clodhopper indeed and does not deserve to be called a human being; he should be permitted to hear nothing but the braying of asses and the grunting of hogs.
Luther's view of music in the Church was not a sentiment that was shared by all of the reformers. He celebrated the organ, while some opposed it. He celebrated using "artistic musical effects" while others felt it needed to be simplified. He wrote music, while some felt only songs found directly in scripture could be sung. Luther, because of his theology, didn't see music as something bad to be avoided but as a part of the creation redeemed by Christ. And because of this view of creation, Luther celebrated the importance of music of all styles and it's relation to the Word of God.