In 1722, when Johann Sebastian Bach lived in Köthen, Germany, he published a book of preludes and fugues in all 24 major and minor keys. This collection became known as The Well-Tempered Clavier, Book One, BWV 846–869. About two decades later, Bach compiled a second book in Leipzig, which became known as The Well-Tempered Clavier, Book Two, BWV 870-893. Bach intended these pieces for the clavie...