I am using these three artists because since 2005 they are the biggest female artists that have emerged onto the pop scene, and still continue to be popular til this day.
Rihanna's first single was released in 2005, while both Katy Perry and Lady Gaga's first singles were released in 2008. Be sure to take into account how much they accomplished in each of their time frames.
Since their debut, who has made a larger impact with both their music, image, music videos, tours etc? On a
global scale.