What song is this from Something Borrowed Movie?

If you've seen the movie "Something Borrowed" I'm looking for the name of the song that is played right before Rachel injures herself dancing. She's watching Dex and Darcy dance, and some of the words of the song go "oh oh oh, we came here to party" I looked up the lyrics and I came across Sarai Howard "came here to party" as possibly being the answer, but I can not find that song on ITunes or any other MP3 site. Any help appreciated!