Here’s a prescription for convalescent hippies you oughta know… Webster’s defines serendipity as “the faculty or phenomenon of finding valuable or agreeable things not sought for,” making it an apropos name for The Serendipity Singers.  The group was formed in 1963 at the University of Colorado in the days when The New Christy Minstrels could sell one million copies of “Green, Green” and folk music was being happily served to the masses by clean-scrubbed young men and women with a spoonful of sugar.  This was before Beatlemania, and before Dylan went electric,…