When you go to a country side, a shoreline, a mountain range, a forest or your own backyard, one can see and feel there is a difference in that which is man-made and that which is not. Now, a human being can create marvelous things, things that have a purpose. Nature does not make anything without a purpose. when you are out in the woods or the ocean beaches, or other parts of the natural worlds, can you hear-feel their music? There is pitch, rhythm and timbres flowing continuously. And the melodies and harmonies they create outside and inside ourselves...
Think of how the birds sing. Their singing is for a reason and expresses the land in which they live on. Different birds have different songs just like the composers who don't write all the same music. In various parts of the world the birds, trees, animal life, soil, insects were born on that land and function according to the nature of that geography and climate. So the music that comes from all over the world has variety and flavors reflecting and expressing the land and culture of the people at any particular time.
So! What about these particular times? Are they fashions or periods of time that have their own uniqueness locally and globally? We have named periods of time haven't we? Renaissance, baroque, classical, romantic etc. are some examples people have named as distinct periods not only for music but for architecture, painting and fashion too. So we have all these eras of time and change. Time is change but what are the things that don't change?
For sonic music, you will always need rhythm, pitch and timbre in one form or another. For anything in art, architecture and fashion you will need a medium to work through. It would be interesting to see if the song of the bluejay has changed in the past 200 hundred years as much as the various periods in music have. I doubt it, but I'm sure there could be some change because of how the environment has changed.
NOTE: Video 2 is located in the pervious post