Delete songs from a playlist
- Open Music > Playlists > tap the playlist.
- Press and hold a song, or tap the More button at the end of its row.
- Tap Remove from Playlist.
The song stays in your library and in any other playlist it is in. You can do this only in playlists you made.
Checked against the LuneOS code and installed apps. Nobody has tried these steps by hand yet, so tell us if something differs.