Each year, over 1,000 cities around the world throw citywide music celebrations on June 21.It all started 39 years ago in France.In 1982, France’s Ministry of Culture dreamed up an idea for a new kind of musical holiday. They imagined a day where free, live music would be everywhere: street corners and parks, rooftops and gardens, storefronts and mountaintops. unlike a typical music festival, anyone and everyone would be invited to join and play music, or host performances….