Confused About STEMS

So I bought an S8 to experiment with STEMS and love it so far. I've been purchasing all my STEMS from online sources like Beatport, Juno etc. but a lot of the songs I want are not in STEM format so I was hoping I could buy the single track I want in .WAV or .AIFF and be able to split the different parts of it out like drums, bass, synths and vocals as individual .wav files to be imported into the STEM creator tool to turn it into a STEM that I can use on the S8.

All the searching I've done is really confusing me. I've heard once a song is created it can't be split into separate parts. So how can STEMS be created for older songs? I thought software like Ableton Live had the ability to do that but I'm not gonna drop $99 to $499 for a copy of it unless I'm positive it can be done.

Is this even possible or is the STEM creator tool basically just for a producer that already has his tracks split up and wants to compile them into the .STEM.MP4 format or is this something the general home user can actually do with his favorite purchased tracks?

 

Is this even possible or is the STEM creator tool basically just for a producer that already has his tracks split up and wants to compile them into the .STEM.MP4 format

This is your anwser, you cant make normal tracks into stems..

 

Ok, thank you

 

For a long time I wanted the vocals from tracks to be able to mix them, I actually bought Ableton Lite, originally to warp my favorite music to be able to sync and use tracks.
Now even with stem tracks I find that mixing doesn't need much of the music, in fact less is more for me.
I kind of imagine it as humming a tune and the main part or part I like of a song. That's what can be mixed.
I guess what I mean is you probably shouldn't use or mix whole full length parts of any popular music. So if possible maybe try finding parts that work and mix those. It still is not easy though, I only have about 3 mixes I would let anyone hear that are from popular music or recognized content that I separated samples and made a whole new version of. The rest is mostly standard track to track mixing with effects.
It's quite hard to really make a new mix of already awesome music mainly because just adding a beat is not usually enough.
I'm not giving up though and neither should you, I am now just getting good with ableton after about 3 years of almost not stop use, along with that a couple of small parties (wedding) and practice mixing. Its starting to come together. I originally started mixing and trying to make music around 1997.
A lot of things have happened to make it easier, but it has taken quite a long time to make sense of it all and really do what I wanted to when I started.
I kind of wish I had started with production and sound design. But whatever...
My best advice is read some basic mixing tips books and basic sound design books, you can get them digital from iTunes or Google. This is not an option I had when I started. Also most software and hardware has free downloads of the user manuals, I have found much of what I need to know before even buying. And sometimes looking through manuals first I decide that really cool new product is something that is not worth it to me.
Sorry if this is long and boring but, hope it helps.

 

Thanks for the great advice!