Monks of Abhayagiri Monastery chanting together. [photo licensed under Creative Commons License, CC BY-NC-ND 4.0]
Chanting is a very ancient Buddhist tradition, and one which is still practiced in Buddhist monasteries.
Long before the Pali canon was written down, it was preserved as an oral tradition. Chanting likely played a significant role, aiding the memorization of extended texts. By chanting together, monks could hear whenever their chanting deviated from that of others. This was, no doubt, a great help in preserving the texts from one generation to the next.
For many listeners, these chants have a calming effect and are simply a joy to experience. For others of us, the primary significance lies in the meaning of the texts themselves. These are two different ways to relate to these chants. May you find value in both.