Over time there have been many schemes for representing music, and in Western cultures the most prevalent has been the use of the notated score. e data structure in the Python music library takes this tradition as a starting point and builds upon it. A computer representation of music, or anything else, needs to be quite detailed because the computer’s interpretation is very literal, even moronic. As we proceed through this book the level of detail in the music representations will become more ne-grained, but for now many assumptions are made to keep the task manageable.