Me neither. This has to be one of the most irritating problems that I've ever had with iOS (and I've been there from day dot!). The history of getting my music onto my phone:
1) Bought phone, 128GB iP6. Plugged it in, restored it from a backup.
2) Set it to sync all music over USB, left it overnight (approx 65GB worth)
3) Came to it the following morning, seemingly synced. Started playing music, each track apart from the ones I've purchased from iTunes skipped and said it wasn't on the phone
4) Re-synced via USB, "Other" storage in the iTunes summary was over 20GB. Neither music NOR apps synced.
5) Re-synced *AGAIN* via USB, music still didn't copy across
6) Restored from backup, re-synced, no joy
7) Restored as a new phone, re-synced over USB, no joy.
8) Turned "update via wifi" off, restored from backup, synced overnight, all music FINALLY transferred to the phone
9) Enabled "update via wifi" again, music appeared but with no artwork
10) synced over wifi overnight, phone's name changed back to just "iPhone", only purchased music was visible, but with 50+ GB in the "Other" section in iTunes summary. Used iFunBox to remove the "music" folder from iTunesControl and hopefully reclaim it
11) Phone no longer visible on iTunes, despite reboots and restarts, even after renaming the phone back to its original name.
12) Now restoring via USB again after turning off the wifi sync yet again. Stuck on "waiting for changes to apply"
Really, really annoyed by this, Any wireless sync that "works" seems to block off 90% of my library, despite the files being on the phone. I have a central media server, and Wifi sync is the best way for me to sync mine and my partners' phones, and so far it's taken over 24 hours of messing about, wiping, restoring, syncing and repeating the whole process to get back to the same scenario I was in before I got the **** thing!