One of the most frequent modern criticisms of classical music and the people who play it is the aloofness of the form; the grand, formal presentation of performers who don’t speak, don’t interact with the audience, and acknowledge accolades with only a stiff bow. Offering the counterpoint to that perception is cellist Yo-Yo Ma, who seems to delight in passing on his passion for music to the next generation of young performers, and thinks nothing of offering a starry-eyed 17-year-old a chance to play alongside him.