BACH’S FIRST BIOGRAPHER JOHANN NICHOLAR FORKEL described the family gatherings:
“[T]he first thing they did… was to sing a chorale. From this pious commencement they proceeded to drolleries which often made a very great contrast with it. For now they sang popular songs, the contents of which were partly comic and partly naughty, all together and extempore, but in such a manner that the several parts thus extemporized made a kind of harmony together, the words, however, in every part being different.”
This painting is entitled “Bach Family Morning Devotions.”
As the family had been Lutherans since the time of Martin Luther, they undoubtedly sang from the Lutheran psalter.