Cotton Mather was dealing with a type of seeker-sensitive church in his day. He thought that the introduction of musical instruments (especially the organ) was a ploy to entertain the people and steal them out of the Reformed churches.
He saw the organ in the same way that many in today's churches see guitars and a drum set. I guess that many of us, upon reflection, need to reconsider our positions on these things. What is the difference between a guitar and an organ? Is there any difference?
If we believe in doing what God tells us to do in worship, should we not have all of the instruments that God says to use in the Old Testament and not one that was invented in the 1600s? Or should we reconsider the whole thing? Why did ALL of the Reformed churches sing a capella? What does God want from us?
"Attempts to propagate the Church of England among us, by a most conspicuous and marvelous blast of heaven upon them, do very much come to nothing. Even the organs introduced into the chapel in this metropolis of the English America, signify very little to draw over our people unto them." -Cotton Mather, in a letter to John Stirling, 1714.