Introduced as a 15-year-old living with stomach paralysis and nourished via a feeding tube, Emma Kok steps beside André Rieu and the Johann Orchestra to deliver “Voilà” in English, her Voice Kids–honed control riding a restrained waltz as the strings swell and the hall holds its breath. As the arrangement widens and she folds in a tender “Heal the World” refrain that turns the audience into a chorus, the moment crests—let’s watch the video to witness it unfold.