DIYbanter - View Single Post - (OT) How do they remove the vocals on KARAOKE music?

Nil[_2_]

On 13 Jan 2013, wrote in alt.home.repair:

Just something I've never been able to figure out.
How do they remove the vocals on KARAOKE music?

Most commercial karaoke music is re-recordings, with people or
synthesizers duplicating the original performance, minus the vocal of
course, Some of this is quite faithful to the record, but you can
usually tell that it's not, either by the performance or the sound
quality.

This isn't used much for commercial karaoke, but you might be thinking
of this: there is a technique called "OOPS" (meaning [O]ut [O]f [P]hase
[S]tereo. You reverse the polarity of one of the stereo channels, then
sum the whole thing to mono. This results in everything shared equally
by both channels - which is usually the lead vocal and bass - to
disappear. However, anything even slightly off-center will still be
heard to various degrees - that includes reverberation. The end result
is that the bass usually is gone, and the main vocal is mostly gone,
but you will still hear ghost traces of it.

It would be possible for the producers of the original records to
create special karaoke mixes of their records that include the original
instruments, but that eliminate the vocals. I don't know for sure, but
I think this is rare.