I was actually gonna try and see if I could make one with Audacity. I was gonna import both the original & karaoke and use the Noise Removal tool to sample and take out the background music. ...Sadly, Audacity isn't compatible with either AAC (iTunes) or WMA (Windows Media Player) files, so I couldn't import the files to begin with. And I don't wanna deal with file converters, (which I tried one or 2, and I question if
they're even compatible with AAC & WMA files) so, if I ever figure something out, I'll try it.