Music files don't copy from iTunes to iPhone, appear grey with a dotted circle When I drag music files from iTunes (desktop) onto a connected iPhone, many times the files just don't copy to the iPhone - the tracks appear in the list on iPhone, albeit grey and the most-left column is a dotted circle with a to me unknown meaning (it might be a progress bar really...).

iTunes 12.0.1.26 (OS X Yosemite)

You can see some of the files copied, while others did not, in the screenshot:



The dotted circles are in the left-most column.

I'll list some things to rule out:


Not using iTunes Match.
I do have enough space on the iPhone. It's a new iPhone 6 Plus 128 GB, with about 60 GB free space.
I do have "Manually manage music and videos" selected.
I can copy some files, some files just won't copy. Even in the same drag manoeuvre, some files would copy and some will not.
Ignore all the rest of this crap, all I did was change the name of one of the songs that wasn't syncing.  After I did that I hit sync and they all started syncing.  Hope this works for whoever reads.