Complex sentence: He studied, worked and composed in Breslau and Halle, then an eighteen-month sojourn in Italy from 1713--where he met Antonio Vivaldi in Venice--rendered him "au courant" with the latest musical taste.
Split into simpler sentences: He studied, worked and composed in Breslau and Halle. Then an eighteen-month sojourn in Italy from 1713--where he met Antonio Vivaldi in Venice--rendered him "au courant" with the latest musical taste.