Book excerpt: Johann Sebastian Bach's "Notebook for Wilhelm Friedemann Bach" is a collection of keyboard music Bach began compiling in around 1720. Most of the pieces included are better known as parts of the Well-Tempered Clavier and the Inventions and Sinfonias. The authorship of some of the other works in the collection is debated. The comb binding creates a lay-flat book that is perfect for study and performance. 62 Selections, 123 pages.