Remove difference between tracks

Hello guys,
So, I have two songs to work with, they are both the “same” song but in differente languages, the same singer recorded it twice with the same instrumental track but in different languages. What I want to is to use audacity to take both tracks and remove everything different between them (in this case, the voice) to have left only the instruments. I tried that trick of inverting one of the tracks and so on, but the final result is the exact opposite of what I want (I have clear voices with low volume instruments).
Is that anyway I can do this?

I think the best you can do is add the two songs together and then divide by two. Each of the singers will appear together, but at half volume.

Vocal removal, sucking out the lead singer, is a dead simple arithmetic job. Anything the same in both tracks vanishes. The other variations seems like they should be simple as well, but they’re much more complicated or impossible to do well.


What format do the songs have?
Two times mono or stereo?

Both .flac and stereo

You can try my tool in

to isolate the center.
In order to do it properly, you have to rearrange the two files. Split them into mono.
Then, make a stereo file out of the left channels and also the right channels.
The center should now hold the common audio, namely the instruments.
You can then try to isolate the center in those tracks which gives two dual-mono tracks.
Split those agin and delete one channel from each. Make the remaining two mono tracks into the final stereo track.
There will probably still be a lot of vocal residual, especially where the lines share similar content.
You can use your first version (where the voices were clear) as a noise profile and apply it to the just made stereo track.
I wouldn’t expect too much though.