Downloaded music from old to new iphone.. What a mess, no apple support level2 folks can answer

Moved to new iPhone16 and been using iCloud. All went well but

none of my downloaded music synced. Called apple several times,

no one knows an answer.. Fortunately, I have the downloaded music in

a old laptop but no clear instructions.. Any Help?

• My iphone 16 is up and running and restored from iCloud backup. No issues.
• How do I JUST COPY (Just Copy) my downloaded music from my old windows computer (though I moved to MAC but I can still see the downloaded music in that old laptop) to my new iphone16 w/o disturbing anything on my new iphone16..
• If there is no way that I can do it, I will live with it..