Solved: this will probably be difficult.

i heard a song today, and i could have sworn it was karen o singing, but i listened through all of her songs that i could find, and i couldn't find this song anywhere, so it might just be someone that sounds similar to her. i have no idea what any of the lyrics were because i was in a store when i heard it and it was difficult to figure out the words, but the notes were something like:

F# G# F#
F# G# F#
F# G# F# G# E C# B

haha i'm sorry that might not be much help, but i am desperate and i really want to find this song!!!

if someone has any idea, i would be really grateful!

She's in the group The Yeah Yeah Yeahs. Maybe it's one of their songs.

you know what, it was the yeah yeah yeahs! its called "let me know".

i have all of their full length albums, but i guess it's on an EP that i hadn't heard of. i just found it online. thank you for your suggestion! =D