Conversation so far:
What sort of impact dd Kelly Clarkson have?
Kelly Clarkson has scored 100 number ones on the Billboard charts and sold over 25 million albums and 45 million singles worldwide.
how did Kelly Clarkson rank on the billboards?
Kelly Clarkson became the first artist to top each of Billboard's pop, adult contemporary, adult pop, country and dance charts.

Question: What was her number 1 hit?
Self-contained rewrite: What was Kelly Clarkson's number 1 hit?