Beyonce has Pepsi, Taylor Swift has Diet Coke. Swift’s new commercial for Diet Coke premieres tonight on “American Idol.”

[More after the jump...]

The 30-second spot, embedded below, features Swift penning the lyrics to her current hit (and speaking them in a much softer voice than we're accustomed to), “22,” as listeners— some on the far side of 22, others still yet to reach it— sing the song in their car, at work as a short order cook, or just strumming their guitar.

The ad, filmed in Nashville, is part of a multi-media roll out with Swift that will also include print and digital advertisements.    

Swift, along with dozens of cases of Diet Coke, we’re sure, is currently out on a U.S. arena.