Let's see. In my country (Argentina) Lady GaGa is very popular, while Katy is not THAT popular. Her tour helped to rise her image a little bit. Also Rihanna is more popular than her.
Adele who?. Much Music and MTV play her videos, and you can find her in some radios, but that's it.
Beyonce is known. That's it.
Ke$ha who?
Kelly Clarkson who?
Nicki who?.
Jessie J? You can listen to "Price Tag", but don't ask for more.
Kylie and Madonna are well-known artist.
Pitbull, Shakira, Guetta, those are popular names.
The "popular" thing is that
****
called Reggaetón and Cumbia. My god, HORRIBLE.