Final answer:
Susan Boyle sang "I Dreamed a Dream" from the megamusical "Les Misérables" on "Britain's Got Talent" in 2009, exemplifying the continued success and emotional impact of Broadway classics.
Step-by-step explanation:
Susan Boyle became a global sensation on "Britain's Got Talent" in 2009 when she performed the Broadway classic "I Dreamed a Dream" from the megamusical Les Misérables.
This musical, which is one of the many successful megamusicals of the 1980s alongside others such as "Cats" and "The Phantom of the Opera", often grossing into the billions, proved that shows with massive appeal and stunning productions could create unforgettable theatre experiences.
Boyle's performance not only highlighted her remarkable vocal talent but also the enduring appeal of well-crafted Broadway hits that have the power to connect with audiences on a deeply emotional level.