Transfer iTunes Library Music from iPhone to new MacBook Air

[phl92]

My MacBook Air M1 finally today arrived My first Macbook (ok I had the MacBook Pro 2020 version for 2 weeks).
So on my iPhone 11 is around 15 GB iTunes Music stored which is from my old iPod stored on iTunes on a old Windows laptop. I can listen to this Music offline on my iPhone 11 without problems, and I am also a 3month free Apple Music subscriber (was included in the buy).

Ok, so now I also want to have my Music Library of my iPhone on my Mac. But it seems not so easy as thought. I can see all my tracks, but most of them cannot be played.
I connected the iPhone 11 with the Mac but still nothing happens.
I did now a full backup of my iPhone 11 on my Macbook. Took around 30min, but still I cannot listen to my Music, neither can I find where this backup is stored.

Can some Apple expert help me out ?

 

[phl92]

Ok I think I am just freaking out right now. After disconnecting my iPhone from my Mac, my music on my iPhone disappeared?!?
What the hell?

edit: I am super mad, most music is away from my iPhone now!!! I was just happy with my new Mac Air and now I remember why I made an circle around Apple products for more than a decade. The last time this happened to me is 15 years ago, when you connected an iPod to a empty iTunes and it deleted all.
I did say by no means that he should touch my Library on my phone.
So all I still have is my backup on my old Windows Laptop.
How can I proceed the safest way to get my files back and have it finally on all my devices? (Gosh Apple you suck so hard!!!)

 

[Dave Braine]

Unless this has changed with the advent of syncing iPhones by using Finder instead of iTunes, you can transfer music from a Mac to an iPhone, but not the other way round. So, as you found out 15 years ago with your iPod, if you sync an iPhone that has music on it with a Mac that has no music, it will delete all the music on the iPhone.

Unless you stop the sync straight away, and untick the Sync Music option.