

In some music this could mean removing instrumental parts.

Note, this removes everything panned in the center, not just vocals, and returns a dual mono result (both channels have the same audio). The underlying technique in Audacity is to split the stereo track into its left and right channels, make both mono, invert all (or a selected part) of one of them then play back the result. If the vocals are panned in the center of a stereo track the so-called "vocal removal" technique can sometimes be effective by removing what is common to both tracks (that is, the vocals), leaving behind what is different (that is, the instrumentals). Case 1: Vocal Removal with vocals in the middle and instruments spread around them
