A weeklong conference on the music and legacy of Johann Sebastian Bach is going on in Toronto, and William Littler finds himself wondering what it is about Bach that continues to so fascinate and inspire musicians, audiences, and scholars across the generations. “Perhaps it is the very ability of Bach’s music to survive a variety of approaches that provides a clue to its universality. As [conductor Helmuth] Rilling put it, a bad performance of Bach is still Bach, but a bad performance of Handel isn’t very good.”