Q: Music Won't Sync From Itunes Correctly

Here is a solution. It's not the definitive solution but for me it has worked until we hear something from Apple, you have to be an iTunes match subscriber . Restore your phone, do the sync all music and after that turn on music match and stay away from iTunes, it's terribe and sad but that's the way to have all your music intact and only adding new stuff via iTunes match. This is the path Ive choosen.

while that can be deemed a solution, I personally find that paying apple $25 to get a  brand new $950 iPhone to sync music successfully is a slap in the face. If you're like me and bought a 128G iPhone to mobilize a large music library among everything else it does well, the last thing you want to do is pay for a service to stream it over the air; besides that service is governed at 25K songs.

What does work, and NOTABLY over wifi syncing: Select all of your DRM AAC purchased & protected dupe songs in iTunes/ thrown them in the trash/ reboot/ delete the nonsense-of-an-attempt of a prior sync on your iPhone (i.e., delete all the music off your iPhone)/ re-sync, let it bump, (i.e., let iTunes do it's work uninterrupted, it'll take awhile. Go do something and stop watching paint dry on the wall). You'll be able to transfer most of the selected audio.

you'll probably see some nonsense on the screen showing some blown-out data compositions on your iPhone, like pictured below. But whatever, this should be old news in a few days when Apple updates to 8.1 with Apple Pay, bug fixes...and hopefully prices and pre-orders for that new watch. Cheers.

I Am afraid future releases as we now now it, like Yosemite and iTunes 12 don't solve this.

So you're using ApplePay? You have iOS 8.1?

the terms of use of the developer agreement forbid me to answer that. :-)

Well...if it's true that near future OS releases do nothing for the problem, I suppose now is a great time to clean out the cobwebs in my iTunes library, and make a trip every month to the Genius Bar and let Apple keep handing me new devices   until a simple transfer works or until they manage to resolve it.

...curious: how many among us use a service like TuneUp? Notice any weird syncing with playlists created by TuneUp even though you didn't select the playlist to transfer?

I too am back to square one, corrupt/flawed music transfers, erased and reset my iPhone 6 Plus over 5x now. At the time of this writing, I can't even move a single genius list of 124 songs to my iPhone. Something is really wrong.

...interesting turn of events: I went into my iTunes account and deauthorized all devices, logged out of my iCloud account and reset my iPhone 6 Plus on a fresh restoration. Did a small 100-song genius sync from my iTunes and it went perfectly. Now I'm syncing all my top rated music (~8,000 songs), barring purchased/protected AAC DRM files, which are unchecked (normally, this list is 11K songs). So far, the sync is humming along.

Next test tonight when I get home is to 'check box' all the DRM music in my iTunes library and try to move those.

Also, no special unchecking or checking this-that-or-the-other boxes in the iPhone summary page. Straight no chaser, and the thing is syncing via wi-fi, cable, whatever. Fingers crossed. Should I have another failure sync with the DRM stuff, I can isolate the issue to something there, which in my case is like 3K songs. But, maybe...just maybe...the de-authorization of devices in my iTunes account may have pulled the hypothetical splinter out ....

Another idea came across my mind: Over the past 10 years, my iTunes library has accumulated DRM songs from ex-girlfriends (and an occasional attempt to help a computer-less friend recover their damaged iPod content) ; these songs still play fine on iTunes, strangely, but that said: how do I remove DRM content in my library that is not exclusive to my Apple ID without going through each song and looking at the details window--(which shows who the song belongs to)?

Duuude!! Woooah, think I figured it out! .(..all DRM content fully transferred too--without 'Match" service. Man this is awesome. Here's what I did):

-wipe the iPhone 6 Plus to a clean restore

-logged into my iTunes account and de-authorized all devices

-went to the iPhone summary tab: I left wifi sync checked, sync on checked songs & vids was checked, auto sync was checked.

-went into my music tab, selected a small genius list to start as a test, ran perfect, next I transferred a huge list at 8K songs, then finally my DRM/Apple-purchased audio. All good.

Caveat: I inadvertently erased all my iTunes library playlists during a failed attempt this morning, but not really at a loss because I could bring it back via TimeCapsule. Not sure if that had something to do with the smooth syncing that's occurring now, I doubt it. If I had to pin point the cause, for me at least, I'd say the issue was my Apple ID, device authorizations and my iCloud. Check it out, see if it helps you.

I received my iPhone 6 Plus 128GB over the weekend, and spent 3 days trying to sync my music to it.  Reading all these posts on here just aggravates me more as this is a serious problem and the fact that it even exists has me questioning QA at Apple.  After attempting to sync various playlists only to have 1 sync then the next failing and then having music that had synced up properly be removed by a subsequent hosed up sync I finally decided to just try to do one large sync of my entire library and avoid plugging my phone into my computer again until Apple fixes this problem.  Unbelievable that I should have to resort to that with something that has been so easy for years.  I restored my phone half a dozen times during this process and found that no matter what the initial sync consisted of (iTunes, cd ripped, etc...) it was always successful.  Subsequent attempts would just start messing things up.  I've removed all duplicate items from my library.  Even tried this process on both my Windows desktop and MacBook Pro.  They both yield the same results.  Finally ended up doing one final restore of the phone and then doing a full sync of my entire library.  I am stuck fumbling around manage my music on my phone instead of with iTunes but I at least have my music for now.  I hope this helps someone.  I also hope that Apple addresses this soon as its a pretty major issue and a massive inconvenience to say the least.

So, I've been dealing with this same issue with my new 6+ and what has worked for me twice now is choosing what I want synced music wise and then hitting back-up this device to this computer.  It syncs all my music to my phone after it does the back-up and everything is okay.

As someone who suffered through this for a couple of weeks, I want to share what worked for me (so far):

It appears that iTunes match put some tracks in my library that were duplicates of tracks I already had. At least two of those were apparently causing the sync problems everyone is discussing here. When I located those tracks and deleted them (View / Show Duplicate Items) from both my local library and the cloud, my syncing problems ended. I've been syncing correctly for about 3 days now.

I hope this helps someone, and I sincerely hope that Apple finds the cause and fixes this. There's no excuse for this behavior regardless of root cause. Like others who have for years said "it just works", I spent the last couple of weeks losing confidence in Apple.

I blame this, at least in part, on iTunes Match. Signing up for it was a mistake, and I will definitely not renew it.

If iTunes Match seems to cause a lot of this, why is it spazzing out for those who never had it?  I never had iTunes match!  And I haven't had any issue synching to my iPad until tonight when I couldn't get new songs nor new playlists over!  I haven't been able to successfully sync my phone in weeks without having to do the half-*** jury-rig of selecting playlists manually and then selecting all of the genres.  What a pain!

i wouldn't blame iTunes match for this.  Heck it seems almost like it is something to do with the iPhone 6.  I personally have never subscribed to match.  Just hope this is resolved when they put out 8.1.  Worst iPhone launch to date.  Hate to say I waited for an entire month very anxiously for my 6+ preorder and it's been less than the happy times I was envisioning.