Q: family account and separate music libraries

We have a family account that can share all music purchases.  I signed up my son for Apple Music awhile back and everything (100s of songs) he puts in it shows up in the family account.  Now when I go into my account I have to sift through his 100s of songs to find my own favorites.  My daughter in in the family sharing but her library is totally separate, as well as my husband's, so they don't have to see our son's 100s of songs.  How can I make my library separate from my son's library?  Do I need a new Apple ID?  But we still want to be able to share purchased music.  Thanks.