Taylor Swift has scored her seventh #1 with "Back To December" at the top of the Mediabase Country Singles chart.

Jason Aldean and Kelly Clarkson's duet "Don't You Wanna Stay" takes the No. 1 spot on Billboard's Country Singles chart, which marks Aldean's sixth career No. 1.

Jason, who turned 34 yesterday, shared that it's a "pretty killer birthday present," noting, "My family and friends are going to have to work VERY VERY hard to beat what country radio fans have already given me today."

He added, "I am really proud of this song. Anybody who says they wouldn't be nervous to try and go note for note with a vocalist like Kelly Clarkson is straight up lying to you! So, I do feel a huge sense of accomplishment to have pulled it off in the studio and on live TV with her, and then for everyone else to have responded to it the way they did...it's just incredible, and you never take those things for granted."

Jason also talked about performing "Don't You Wanna Stay" live and hinted about his interaction with Clarkson onstage. "Obviously, she can't be here every night and none of my guys even come close to singing like that or looking like that. So we had to do something to kind of, you know, make her part of the show. And so I think it's cool. I think it's one of those things - like everything else - I mean, we're gonna have to work out some of the kinks in it, and kind of get timing right where it kind of looks like she's almost live via satellite kind of thing. I think it's gonna be good. And it's good, like...her part's on track, so...I love the duet for the fact that - if you mess up a song - you can only mess up half of it, you know what I mean?"