Johann Sebastian Bach's Christmas Oratorio consists of six cantatas, performed at six different times between Christmas Day and the feast of Epiphany (traditionally, January 6). The website
Bach.org describes the first three parts:
1. On the First Day of the Festival of ChristmasAnnounces the birth of Christ, and reflects on the Holy Child.
2. On the Second Day of the Festival of ChristmasThe angel appears to the shepherds in the field.
3. On the Third Day of the Festival of ChristmasThe shepherds go to find Mary, Joseph, and the Baby Jesus; the shepherds return to their fields, glorifying God.
The remaining three parts are intended for performance from New Year's Day through Epiphany. The first three parts of Bach's Christmas Oratorio make up today's one hour and eighteen-minute Midday Masterpiece.