Add music from iTunes to iphone

Over the years I burned a lot of CDs into iTunes on a desktop Mac and also downloaded music from various sources. Much of it was sorted into playlists which I used to add periodically to my mobile devices. I haven't been able to do that for several years, presumably due to changes in the iOS. While I now can access music via sources such as Amazon Music and Apple's music app, I'd still like to listen to music from my own library. Is there a way to transfer those iTunes playlists or individual albums?