[TOMT] A Song From The 2000's (I think), Female Singer(s).

I wish I could give more, but I can't. a friend played it on her phone about a year ago, and it's inexplicably stuck in my head right now.

I only know one part of the song: a female singer- singing in harmony with another voice- sings "na na nana na naa\na naa na\na na nana na naaaaa" to a very haunting and catchy melody. I might be one "na" off. I don't remember any other words or sections of the song. I've already tried looking up what I know on Google, and it comes up with nothing. I don't even know if that's the chorus or just another section of the song, or if it occurs more than once.

I can say: I do remember thinking that it must be a female band when I first listened to it. however, I do not remember why I thought that now.

Tip Of My Tongue, you are my last hope. not even the girl who first played the song can tell me who it's by, though she told me to try Matt & Kim. I searched their lyrics, but I don't think it's a song by them.

EDIT: it's not any of the usual results that come up from Google- that's the problem! not Gwen Stefani, or Kaiser Chiefs, or Akron, or Nelly. also, it's definitely not a rap song. as I recall, it's a rock song.

EDIT 2: here's a link of me singing it from Soundcloud. probably should have done this from the beginning. it's not quite the same (I think I'm singing it a little slow compared to the song), but it's damn close and the best I could do.

http://soundcloud.com/powersurge578/reddit-will-save-me/s-5vMlr

EDIT 3: SOLVED!! Thank you, TOMT. you do not know how many times this song would get stuck in my head and I would wonder "who sings that song?" well, now I know: "Lessons Learned" by Matt & Kim. although, since I downloaded their albums a few weeks ago, I would have found it eventually. thank you to Hclarke15, you da man!

here was his comment:

hclarke15 Lesson's learned -Matt & kim http://www.youtube.com/watch?v=bJkymylTNU4 weird music video btw