Of the more than 300 cantatas which Bach composed in Leipzig, over 100 have been lost to posterity. Most of these works expound on the Gospel readings prescribed for every Sunday and feast day in the Lutheran year. Bach started a second annual cycle the first Sunday after Trinity of 1724 and composed only chorale cantatas, each based on a single church hymn. These include O Ewigkeit, du Donnerwort, BWV 20, Wachet auf, ruft uns die Stimme, BWV 140, Nun komm, der Heiden Heiland, BWV 62, and Wie schön leuchtet der Morgenstern, BWV 1.