which software to use for removing vocal from mp3 ?

[tattitsa]

now i using Audacity . . but Audacity is not perfectly remove some song ..any software to use to remove vocal?

 

[Alabalcho]

There is no perfect software. All of these "vocal removers" work by eliminating part of frequencies inside the file, so you will always get "flat" results.

There are plenty of legal (and not) sites where one can get karaoke files.