From a finished song to a sing-along
Official karaoke versions exist for a small slice of the catalogue, and the ones for newer songs are often re-recorded sound-alikes. Separating the original recording gets you the real arrangement, with the original drummer, bassist and producer, minus the singer.
The model identifies the voice in the mix and puts it in its own file. What is left splits into three stems: drums, bass and everything else. This page asks only for those three, so the download contains no vocal at all.