Have you seen this JC Penney ad?
The song is "Unbelievable" by the New York-based Sleepy Rebels and you can listen to two different versions of it on their MySpace page, plus a few other songs by this up-and-coming band. They somehow manage to mix a 1920s radio sound with medieval English folk with indie pop (!) for a result that is totally charming ear candy.
Their album is called World Record - check it out!