In Chapter Three of this excellent dystopian classic we are introduced to "The Gathering," which we are told happens once a year and is when the Singer, an important person in the community, sings The Ruin Song, which is a narrative song that tells the people the history of mankind over the years:
The Ruin Song was lengthy and exhausting. It began with the beginning of time, telling the entire story of the people over countless centuries. It was frightening too. The story of the past was filled with warfare and disasters. Most especially if was frightening when it recalled the Ruin, the end of the civlisation of the ancestors.
Singing the Ruin Song is the only job of the Singer, and, because of the length of the song, we are told that he takes lots of time to prepare and has to rest his voice for days before the Gathering. It is required for everyone to attend the Gathering and hear the Ruin Song, perhaps so that the history of mankind can be remembered by all and that mistakes are not repeated. Elsewhere we are told that reading and writing is only taught to a select few, so the Ruin Song is a verbal narration of history that can be listened to and remembered by all of the community.