Music on my older iMac

[valinda]

I have not been able to transfer my MP3 music on iTunes to my 6s plus. My iMac is either 2007 or 2008 model.
I can however transfer it to my Samsung S8, which I am very happy
about. It would also be nice to get the music on my 6s plus.

 

[ApolloBoy]

What versions of macOS and iTunes are you running on your iMac?

 

[Dave Braine]

The 6S Plus require iTunes 12.3 or later, so that is probably the problem.