Edwards makes the following acute observation about singing in his Some Thoughts Concerning the Revival. Note not only his connection of irreverence to the third commandment, but his insistence that reverence has an “appearance”:
I believe it to have been one fruit of the extraordinary degrees of the sweet and joyful influences of the Spirit of God that have been lately given, that there has appeared such a disposition to abound in that duty [the duty of singing praises to God], and frequently to fall into this divine exercise; not only in appointed solemn meetings, but when Christians occasionally meet together at each other’s houses. But the mismanagement I have respect to, is the getting into a way of performing it without almost any appearance of that reverence and solemnity with which all visible, open acts of divine worship ought to be attended; it may be two or three in a room singing hymns of praise to God, others that are present talking at the same time, others about their work, with little more appearance of regard to what is doing than if some were only singing a common song for their amusement and diversion. There is danger, if such things are continued, of its coming to that by degrees, that a mere nothing be made of this duty, to the great violation of the third commandment. Let Christians abound as much as they will in this holy, heavenly exercise, in God’s house and in their own houses; but when it is performed, let it be performed as an holy act, wherein they have immediately and visibly to do with God. When any social open act of devotion, or solemn worship of God is performed, God should be reverenced as visibly present, by those that are present. As we would not have the ark of God depart from us, nor provoke God to make a breach upon us, we should take heed that we handle the ark with reverence.*
*Some Thoughts Concerning the Revival, in Yale-Works 4:489-90.