The passage discusses how music has evolved tremendously from prehistoric times to today, but one thing that has stayed the same is that a culture's music is influenced by the culture as a whole. It gives the example of how swing music became popular in the 1930s during the Great Depression as it created an upbeat vibe and sense of joy that was otherwise absent during that difficult time period. The passage also briefly mentions that the brain is an astonishing organ and the majority of the central nervous system.