Heresies and Music?

I have been reading Harold .O.J. Brown's book entitled Heresies. I picked it up again primarily because I thought I had none (errors or heresies) but in the last year or so, I must confess, I was a party (a heretic in Brown's definition - heresy is a party) to some erroneous teachings - I did decisional-ism, born-again-ism, altar calling-ism, I did not see from Scripture the Law/Gospel, and although I think I got the Gospel right, I was wrong in turning its proclamation to a proposal. Although I was taught these ism from the ones who pastored me, I am responsible for repeating them . To all the folk I preached to, please forgive me. I am deeply sorry - above all I was wrong etc. etc. How I wish I could preach again the Good News that is better than you think.

Prof Brown, a confessing Reformed theologian, gives a fair treatmeant of all concerned be it orthodox Calvinist, orthodox Lutheran, and heretic ones of all types. There are a few things he admitted that interest me, one of which is when he says that the first couple of hundred years after the Reformation, the Calvinists produced more heresies than the Lutherans.

In P.383,

The first phase of the Reformation took the universal church out of the center of attention and replaced it with the local congregation; this [Pietism] second wave of Reformation, if we may call it that, redirected attention from the congregation to the individual believer. Christians began to sing "I" rather than "we"

I though this was interesting yet it still goes on today.