For seven decades, the Ojai Music Festival has been a laboratory for the special chemistry that results from combining insatiable curiosity with unbounded creativity. The formula is simple: Each year a music director is given the freedom and resources to imagine four days of musical brainstorming. Some have approached their task with caution, fearing that Ojai might be like other places. But, of course, it’s not. More often this unique blend of enchanted setting and an audience voracious in its appetite for challenge and discovery has inspired a distinguished series of conductors, performers, composers to push at boundaries and stretch limits.