In his second cycle of Cantatas at Leipzig, Bach focuses exclusively on the chorale, each Cantata based on the main Lutheran hymn for the occasion. This new ‘chorale cantata’ cycle is announced with a sweeping French overture in the grand Cantata 20 ‘O Ewigkeit, du Donnerwort’. After impressive coloratura from the tenor, we are woken up by the bass and trumpet with the words ‘Wacht auf, wacht auf!’. Cantata 2 takes as its basis Martin Luther’s chorale ‘Ach Gott, vom Himmel sieh darein’, with images of silver purified through fire. Cantata 7 for the Feast of the Nativity of St John the Baptist vividly depict the river Jordan with gracious undulating phrases, and great and powerful floods, dancing waves, sometimes peaceful, sometimes mighty.