as everyone else has said soulseek and nicotine+.
If you want to get your spotify playlists from soulseek use this script: https://github.com/fiso64/slsk-batchdl
basically you export your spotify playlists as a csv and slsk-batchdl will take that and try to find everything on soulseek and download it for you. anything it can't find it'll let you know. it might take awhile, if you have a server I'd run it on that via screen and just let it run overnight (that's what I did)
Keep in mind that Soulseek has A LOT of audiophiles on it so you'll find a lot of high quality audio and FLACs. if FLAC is too big for you and you're fine with mp3s you c an use Nicotine+ to just search for mp3s.
yeah at this point the days of getting everything on my system to "look nice" or look the same is way past me. now I just don't care. everything is set to the default, everything looks different, my system looks like a clown sneezed all over it.