There were two manuscript notebooks, from 1722 and 1725 respectively, presented by Bach to his second wife Anna Magdalena Bach.
The title most often refers to the second one, containing works both by Bach and other composers of the era. Most of the entries were made by Anna Magdalena herself, with others written in the hand of Johann Sebastian, some by sons Johann Christian and Carl Philipp Emanuel, and a few by family friends.
Sometimes the authorship of a piece is indicated in the book, sometimes it is more doubtful. For example, it is possible that the famous Minuet BWV 114 and its partner piece Minuet BWV 115 were composed by the organist Christian Petzold.
