This song is on a current commercial for some sort of low-cal food, like frozen meal or something. It's a first-person perspective of this girl getting showered and dressed in the morning and then walking around and everyone smiles at her because she looks so good. Then she sees herself in a store window and that's pretty much it. Anyway, these are the words I made out from seeing it a couple times the other day:
You brighten up the day, you're a star
And every time we ah ah ah, words fail me
--something something--
La la lalala is all I can say
Around this point it fades out. It's a pretty fast song with a sort of recorded distant type quality to it, but I have NO IDEA who the band is or anything. It's sung by a man.