(Debuted July 3, 1982, Peaked #22, 14 Weeks on the Chart)
The showstopper has long been a part of Broadway shows, but by the 1980s they weren't as much a part of the general landscape of the pop scene as they were until the 1960s. You can blame the decline of the movie musical for that, as they gave way to the rock operas and the occasional project like Grease. However, stage shows were still going strong, and one of them that premiered late in 1981 was called Dreamgirls, which was largely taken from the story of The Supremes but fictionalized just enough to keep from getting sued by Motown.
That play's showstopper was "And I'm Telling You I'm Not Going," which was performed be the character Effie in the play and originally voiced by Jennifer Holliday. The Texas native immediately caught notice, driving the song into the pop Top 40 and the top of the R&B chart. It was the first song from a stage show in several years to hit the Top 40; even Grease had to wait for a movie version before it generated any hits.
Today, the song seems to be better known for Jennifer Hudson's rendition in the 2006 movie version of Dreamgirls, as well as the way it tends to get picked by every big-voiced ingenue on reality-based TV shows as a way of demonstrating their vocal range. While that can be occasionally disheartening, Jennifer Holliday set a pretty high bar with her performance.