First it was Joe Jonas, then it was Justin Bieber, and now we have Katy Perry taking her turn at performing a live fragment of The Viral Hit That Will Not Die, Rebecca Black's "Friday." The cover came at a gig in Melbourne over the weekend, introduced by Perry's lead in of "All magical things...happen on Friday!" Like most of Katy's live covers, her "Friday" is done with an acoustic, heavily stripped-down accompaniment, as she runs through the song's legendary "Yesterday was Thursday..." bridge and unforgettable chorus. (Why do none of pop stars ever dare take on Patrice's rap verse? Cowards.)

"I'm so glad that someone wrote a song about Friday--finally!" Katy cracks at the end of her performance, likely making a not-so-subtle dig at the fact that she got there first with Teenage Dream album track and fifth-single-to-be "Last Friday Night (T.G.I.F.)." Hey Katy, you know that The Easybeats beat both you and Rebecca by over 40 years, right? Let's not get too calendar-territorial here.

For lots more pics, videos and up-to-the-second dish on Katy, be sure to check out her Popdust Artist Page.