Katy Perry is probably wide awake ... Clarkson’s 2010s nostalgia-inducing cover of Perry’s song comes weeks after the “Teenage Dream” singer made a 2000s-era fashion statement at Billboard ...

Prior to that her albums included her debut One of the Boys in 2008, Teenage Dream in 2010 ... some fans thought might be cover art for an upcoming sixth album. Perry herself has not confirmed ...