Evening Prayer (often called Evensong), in the Anglican Church, is the traditional service when people come to church to worship in the late afternoon or early evening. In cathedrals it is usually just the choir and the priests who sing, while the congregation listens, but evensong in parish churches will have more singing for the congregation to join in.
The form of Evensong used today was developed by Thomas Cranmer in the 16th century. There were two kinds of services, called "vespers" and "compline" that used to be sung every day by monks in monasteries. Cranmer took some of the words that were used in both these services and made today's form of Evening Prayer.
The main idea in Evensong is the celebration of the incarnation of Christ: this is the story about Christ coming to the world in the form of a person and living among people. Always used in the service are the words of the Magnificat, the song that Mary sang when she was told that she was going to have a baby who would be God’s son, and the Nunc dimittis, the song that was sung by the priest Simeon who had been promised by God that he would live long enough to see Jesus. Both these sets of words are from the New Testament.