Trials of copying music library from macbook to iphone

Migrated from an old iMac to new MacBook Pro. There is no iTunes anymore- now it’s called Music. I don’t have an Apple Music Account. On the MacBook all my music (I own all my music) is there! The migration worked. I want to move my music library to my iphone. I connect the iphone to the MacBook but it doesn’t show in Locations in a Finder sidebar window. It’s there when open Music and just the other day I backed up my iPhone to the MacBook no problem. To copy your music library from a MacBook to an iPhone, you don’t use the Music app, you use finder- but the iPhone wasn’t showing in the MacBook. I visited the Finder Settings and saw the problem. I had de-selected the Mount CD….and IOS devices! Turning that on and now the iPhone is visible in Finder. Clicking on it revealed a window from which I could “sync” my music library to the iPhone. I hope this helps.