In 1721 a 20-year-old soprano employed at the princely court in Köthen married the court’s Kapellmeister, set to become the greatest composer of the age. As his second wife she married into a young family with four children, and a busy household filled with music. The music book that Johann Sebastian Bach presented to his new wife Anna Magdalena in 1722, and replaced more lavishly in 1725, treats us to a tantalizing glimpse inside this unique family, allowing us to sit beside Bach as a composer,