Ex. 6-1: Bist du bei mir

This aria originated in Gottfried Heinrich Stölzel's opera Diomedes, first staged on 16 November 1718 in Bayreuth. It became famous through its appearance as No. 25 in the Notebook for Anna Magdalena Bach (1725), where it was long attributed to Johann Sebastian Bach (BWV 508).

Anna Magdalena Wilcke was an accomplished singer when she married Bach in 1721. Her second notebook served as a collection of Hausmusik — music for the family circle. Sometime between 1734 and 1740, she copied this aria into her notebook, arranging it for voice and continuo. How a Bayreuth opera aria reached the Bach household in Leipzig remains uncertain — it may have been a well-known tune circulating in the city.

The authorship was only correctly attributed to Stölzel in the 21st century, after the lost archive of the Berlin Sing-Akademie was recovered in Kyiv in 1999. Today, "Bist du bei mir" is frequently performed at wedding ceremonies.