The cantata “I had great heaviness of heart” BWV 21 is one of the most popular and beloved vocal works of Johann Sebastian Bach. Intended for a performance on the third Sunday after Trinity as well as “in ogni tempo” (for any occasion), this work occupies a special place within Bach’s cantata oeuvre. Particularly unusual is not only its approx. 40-minute duration, but also the work’s wealth of forms and sounds. Matthias Grünert, cantor of the Dresden Frauenkirche, put together an entirely new piano-vocal score to this main work from Breitkopf’s Bach Cantata series. His work is supplemented by a revised new engraving of the continuo part.