What is that song?! I need help figuring this out...?

There's this song I heard a while back in a store and I know it used to be in a commercial too, it's sung by a female with a soulful voice, the background music is really mellow and sweet. Sounds a little like Colbie Caillat's voice or maybe Norah Jones? I don't remember any of the lyrics all I remember is her going la la laa la la la la la la la la la lalalala lalalala lalalalaa. Anybody have any idea??