You've heard Peter Bjorn and John's "Young Folks," the insanely catchy tune "built around a whistling hook so addictive that it has helped regenerate an art form long relegated to the realm of dog-walkers, bird-watchers, and the TV-hawked tunes of Roger Whittaker." Guess what? It's a big hit in Beantown! And you know what else? It is responsible for a renaissance of whistling in the hellhole by the harbor.