How to transfer owned iTunes music, mp3's, from old MacBooks to MacBook Air Catalina

An Apple tech couldn't figure this out after 90 minutes, so I kept thinking about it and came up with an old school answer. The new iTunes update recently deleted much of my old cd music on my MacBook Air Fortunately I still had my ancient MacBook. The new Catalina iTunes update evidently reconfigured the music so that old legal cd music and old reel to reel tapes converted into mp3s were unreadable. It did still remain on my iPad Air since I didn't back it up to my computer yet, but I needed to get it back to the MacBook Air. The Apple tech tried moving it up into the cloud, drop box, airdrop and into Apple Music, even tried TimeMachine, but nothing worked. I mentioned I still had my old MacBook, but the tech said that wasn't a help. The tech said, "It was impossible to do. There are no other options available." I said thanks and goodbye and knew there was always a way to do it. That's the beauty about owning an Apple, there is always a way to figure it out.

The steps: I finally did a hard connection through USB ports from my old Mac to my new Air and used file sharing, selecting "everyone read and write." (Old schools remember this as Apple Talk.) I went into the MUSIC folder, not iTunes, compressed it on my old Mac and then put it into my shared folder. I then went on my Air, decompressed it and imported it into iTunes. All my old mp3s and cd music magically appeared. An easy fix. Save your old computer for at least 6-8 months to make sure you don't lose old info. Apple needs to train its younger techs in some old school ways.