“We have three great institutions, but they’re all competing against each other for audiences,” [Victor] Medem says. “You can survive doing that locally, but you will never attract an international audience.” So Medem founded Barcelona Obertura, a project to get the city’s classical organizations communicating with each other and cooperating on projects — the first of which will be a major spring festival aimed at visitors and residents alike (and at turning Barcelona into a classical-music destination).