For your listening pleasure, here's a full-length demo. I decided to use the Jonathan Coulton classic "Re Your Brains", because I can legally share and modify his music under its Creative Commons license.

First, the original:

https://mwcampbell.us/tmp/spleeter-demo/jonathan-coulton-re-...

Now the derived stems:

Vocals: https://mwcampbell.us/tmp/spleeter-demo/jonathan-coulton-re-...

Accompaniment: https://mwcampbell.us/tmp/spleeter-demo/jonathan-coulton-re-...

Note: I'm not affiliated with this project or Mr. Coulton. I just think this is a cool project and wanted to share.