Could you give us a list of pop stars to choose from? It's pretty easy to say someone like Ariana Grande or Iggy Azealia, but they're both only like a handful of years in to their mainstream careers.
If we're talking bigger, more certified artists, I would say either Taylor Swift or Katy Perry because they haven't really had their experimental eras yet.
Overall I'd say Katy considering Jlo was once the it girl. Rihanna isn't the answer here, she's actually one of the most 'impactful', along with Beyonce and Britney.
