#11 Usher: Billboard's The 25 Greatest Pop Stars of the 21st Century

[ThisGuyTony 27,934]

This list is making me nervous for Gaga cause there’s still:

Beyoncé, Taylor, Britney, Post Malone, The Weeknd, Justin Bieber, Pink, Drake, Ariana and who knows if Madonna (chart success thru 2008 and a touring force) and Mariah (chart success thru 2008 and recurrent AIWFCIY chart success) count.  
And who knows who else Billboard might consider