How do people make tracks with authentic vocals?!?

[mthopper]

Hi everyone,

Sorry if this seems like a newbie kind of question, but could someone please explain to me how in the world users are able to make backing tracks for guitarists that include the authentic vocals used on albums by the actual artists? I am baffled by this. It seems like the artists and the record labels would object to this, right?? If there is some place where I can get such vocal tracks, I would gladly pay.

Thanks

[slinker]

They are Guitar Hero or Rockband files or they found the stems somewhere, like youtube.

[riz]

I wonderin too,
it's quite tricky erase tracks from original files almost impossibile but some songs seems remixed by the originals