Now, see, this is a horrible topic name.

Basically, I have an MP3, right, and I want to separate it into two mp3s: vocals and... instrumental, whatever the other stuff is called. Backing? I followed the tutorial
here and took out the vocals just fine, but I'm wondering if it's possible to mute the other... track... thing, and keep the vocals? I fiddled around a bit using the same method as this tutorial but with a few changes, but it didn't come up with anything. I was wondering if anyone knows how to do this?
Btw, I know that there are probably cleaner ways out there to remove vocals and whatnot, but that doesn't worry me; I'm not after an especially clean cut, just rough will do.