 In an early cantata, , Bach marked a repeat of the opening chorus after the chorale.The chorale can be as simple as a traditional four-part setting, or be accompanied by an instrument, or be accompanied by the instruments of the opening chorus or even expanded by interludes based on its themes, or have the homophonic vocal parts embedded in an instrumental concerto as in the familiar , or have complex vocal parts embedded in the concerto as in , in a form called "" (chorale fantasia).In , for the first Sunday in Advent, the beginning of a new liturgical year, he rendered the opening chorus as a French overture.