Even a cursory review of the Apple Message Boards shows iTunes has a problem syncing music to an iPhone — the syncing hangs on “Waiting for Changes” — and just stops — leaving no indication what the problem is, and often times corrupting the iPhone music data beyond repair. The tell tale sign that it was stuck was that while the computer said “Waiting for changes to be applied,” the iPhone itself did not show the syncing arrows.
While researching the problem, I found that it appeared Apple’s DRM on the older iTunes store purchases may be to blame. iTunes would hang on one of these DRM songs and just stop syncing, without giving any status or notification
In my case, I found 5 songs that were file type: “Protected ACC.” Per the instructions on Apple.com, I deleted them and re-downloaded them via iTunes Match to hopefully download unprotected “ACC” versions. Three of them downloaded as ACC. The other two remained Protected ACC. I tried burning them to disc with the intent to reimport; however, the disc would not burn. So, I threw away $1.98 and just deleted them. Then I synced my iPhone and it went fine. So maybe, just maybe, those two pesky “Protected ACC” files were the source of my woes (**** you, Funkmaster Flex!)
