Three Christmas days, three Easter days, and three Pentecost days stood in contrast to the often gray Leipzig everyday life. Daily attendance at church was probably both duty and delight, and good music was not to be missed. The pressure on the performers must have been enormous, especially for Johann Sebastian Bach, who frequently wanted to contribute new own works. He addressed this through a kind of “qualified recycling” of existing compositions: from one-off occasional works, musical icons for eternity were created, such as the cantata BWV 134 «Ein Herz, das seinen Jesum lebend weiß».