Gary Graffman embodies the Curtis Institute of Music. Just as the Philadelphia-based school is simultaneously one of the world’s leading musical academies and one of its best performance showcases for young musicians, Graffman, the institute’s director, is both a consummate educator and a revered performer. He is also 74 years old, and Curtis has officially begun the search for his successor. Curtis is a unique school, housed in an old Philadelphia mansion and offering little in the way of non-musical academics, and it is an old institute tradition that the director must be an acclaimed musician first, and a manager second.