Time and again, critics have swooned over her showmanship, the deep emotion she brings to the music, and her flawless technique — and just when you think it can't get any better, she whips out encores that draw repeated standing ovations. If you haven't yet experienced the astonishing artistry of Olga Kern, here's your chance — and if you have, chances are you're already clearing your calendar to make sure you experience it anew.