Organising music directory?

i normally copy the music file from many friends, making the same song sometimes being copied (as in the same folder) for 4-5 of them. but when i'm using itunes to track down the same music file, its just display the same file which have the exactly same file name. for e.g song from robbie william, Angel. (file 1) = Angel (Robbie Williams).mp3, (file 2) = Robbie_Angle.mp3. and these 2 music file cannot be detected as same file. is there any software which would do the search base on % of accuracy. let say we set accuracy to be 50%, so it might help to trace both File 1 anf File 2. thanks!