Songs in playlist - Apple Music I have an apple music subscription and then decided to make some cool playlists.

But now, my library is FULL of albums that I never play outside of my playlists, an ugly ugly nightmare. I guess my question is:
How can I have songs in playlist but not in the library?

I don't want to see them outside of the playlist!
Short answer is - you can't.

The Library is your total structure, containing everything.
Playlists are made from the overall structure.

You can delete a song from a Playlist without removing it from the Library - but if you delete a song from the Library, it will also delete it from all Playlists.