Problems with syncing music from iMac to iPhone

I am trying to move music from older iMac (High Sierra) to 8 plus iPhone (current iOS). I tried using iTunes and had no luck. When I connect the iPhone with either a USB cable or WiFi I see the iPhone in the side bar in iTunes. It shows that all the songs I have on the iMac are on the iPhone. When I do a manual Sync, the iMac goes through the 4 step process to Sync and I get no errors. iTunes is also set to automatically sync when a device is connected. However, the iPhone Music app does not show any songs at all. I can play music through the iPhone by controlling it on the iMac from the sidebar.

I tried using the Finder to move the music, but the iPhone does not show up in the Finder sidebar. I checked the device manager and is shows that the iPhone is connected via USB.

I have no problems with Photos. When I connect the iPhone, Photos automatically opens.