http://youtu.be/gWGLAAYdbbc

Cool video about sound

Very interesting.

I remember being in grade school in Chicago when the B-58 Hustler's would fly over at supersonic speed.  It was not only very loud,  it was a sound that rattled the windows and your insides.  Scary.  The nuns would have to spend awhile getting us back on track because we would be so excited.

I'm glad our nation decided not to allow commercial supersonic flight.  It sure would ruin our musical listening experience.