I’m using Windows 10 and Audacity 2.3.2
I’m a guitarist and I’ve recently been transcribing a few different pieces of music that I cannot find any tracks of the instruments in the song isolated anywhere online, which I usually use to help me in transcribing songs if they’re available to me. However, I’ve learned that if I can get an MP3 of the song, put it into Audacity, split the stereo track, and invert one of them, it works out pretty great in allowing me to hear certain tracks clearer. From what I understand, this works by panning tracks originally panned left or right into the center and making central tracks more quiet. Is there a way to do this for central tracks, or specifically for tracks panned to a certain side? (as in only the tracks panned to the left, and not the right panned or center tracks) Any help with this, or any information that could aid me in transcribing music, would be greatly appreciated. 
Center Pan Removal is an interesting trick. Audacity has a pre-baked effect so you don’t have to go through all that work yourself. Center Removal and Isolation.
https://manual.audacityteam.org/man/tutorial_vocal_removal_and_isolation.html
That may be enough to do what you want, or at least help a little.
These tricks aren’t as versatile as you think because you’re not really remixing the original show and the result has no good relationship to the original production. But you’re not trying for a musical result, so that may be enough.
We officially can’t split a mixed song into individual voices, instruments, and sounds which seems to be your goal.
koz
Isolate center …
https ://manual.audacityteam.org/man/vocal_reduction_and_isolation.html
Mid-side decoder plugin may be faster …
Thank you! I’ll try it out in a bit. I didn’t realize that there was already a way to do this within Audacity, I guess I should have looked harder haha.
Also, I’m not necessarily trying to create a good sounding mix. I just want to be able to hear certain tracks more clearly, so I can more accurately transcribe them, and I believe that this will help greatly with this. And I do know that songs can’t be split into their individual parts after it’s already been mixed, however, this is the next best thing, as far as I’m concerned.
Artificial Intelligence is nearly there … https://youtu.be/IHSGrGXp_oo
I get the message, “Video unavailable
This video contains content from WMG, who has blocked it in your country on copyright grounds.”
The (free) AI software is called Spleeter … https://www.youtube.com/results?search_query=+Spleeter
Thanks, Trebor. 
There’s also the “Channel Mixer” Nyquist plug-in: https://wiki.audacityteam.org/wiki/Nyquist_Effect_Plug-ins#Channel_Mixer
Instructions for installing Nyquist plug-ins: https://manual.audacityteam.org/man/installing_effect_generator_and_analyzer_plug_ins_on_windows.html#nyquist_install