BOSTON — “Ten years ago, I was a homeless heroin addict, now here I am on stage at Boston Calling,” said Justin Clancy, wiping the sweat from his forehead and basking in the love and applause generated by a large audience. The 29-year-old Peabody native had just finished his spectacular half-hour set Friday afternoon on the Orange Stage at this premier music festival. His … [Read more...] about Peabody’s Justin Clancy finds his Calling