Hi swhitegsp,
Welcome to the Apple Community,
where some of us do our best to help each other troubleshoot.
This article may help find those CD files .
View files and folders in Files on iPhone:
(NB: Scroll to "Find a specific file" or folder)
https://support.apple.com/en-au/guide/iphone/iphc61044c11/14.0/ios/14.0
Wondering which Operating System is on your MacBook Air.
Apple support has articles online that can guide you.
You might want to browse these articles, and choose what works for you.
What happened to iTunes?
https://support.apple.com/en-us/HT210200
Download previous iTunes Store purchases in Music on Mac
https://support.apple.com/en-au/guide/music/musf4e9226b/mac
Connect iPhone and your computer with a cable
https://support.apple.com/en-au/guide/iphone/iph42d9b3178/14.0/ios/14.0
Transfer files between iPhone and your computer
https://support.apple.com/en-au/guide/iphone/iphf2d851b9/14.0/ios/14.0
OR
Sync content between your Mac and iPhone or iPad.
(NB If you delete a file on one device it will also delete from the other next time you sync.)
(NB: Choose your Mac Operating system at the top for accurate info:)
https://support.apple.com/en-au/guide/mac-help/mchlde9a31f1/mac
Or
Use iCloud Drive to store documents on your Mac, iPhone and iPad
(NB: Choose your Mac Operating system at the top for accurate info:)
https://support.apple.com/en-au/guide/mac-help/mchle5a61431/mac
Hope this helps you get organised with your music files on your Mac :)