Renoise works just fine in Ubuntu 16.04 (although I heard it's not that good in 18.04). It's very cheap but pretty powerful. You can try it with almost fully functional demo version, and full version costs just 68 EUR.
Check out: https://github.com/deezer/spleeter Also if you follow my YouTube I will do a very basic tutorial about referencing soon: YT: https://www.youtube.com/channel/UCk2ZvGBL0CfvtDmKJJz_4fw (in about 2-3 weeks)