Songs appear once in iTunes; listed twice on iPhone 5s (iOS 7)

What do I need to do to prevent the iOS 7 Music app from listing songs twice when the song should only exist once?

I sync a selection of playlists to my iPhone 5s from iTunes 11.1.5 on my iMac running OS X 10.7.5. For at least one artist, album tracks are listed twice on my iPhone despite appearing only once in my iTunes library. I count 16 duplicates out of 53 songs for this artist on my phone. (The artist is Front 242, which I mention mostly for my own reference.)

I checked my iTunes library on the iMac, and I only have one copy of the affected songs there.

I am not using iTunes Match.

Curiously, during playback, songs are not repeated if I move forwards or backwards through a list that includes duplicated songs.

What I tried

In an attempt to solve this, I unchecked "Sync Music" and applied the change with my iPhone connected to my iMac, so all songs were removed. Then I checked "Sync Music" again (and thankfully my previous selection of playlists was preserved), and the music went back on my phone. Same problem.

What I didn't try

I haven't tried marking either individual albums or the artist for inclusion on my phone, just one or more playlists that include these songs.

I haven't tried swiping to delete individual songs, because I'd first want to determine all of the playlists containing that song, and do a time-consuming before-and-after check on my phone to ensure that removing the apparently duplicated song doesn't change my playlists.

Solution 1:

What I would try:

1. Make a current backup your iPhone via either iTunes or iCloud.
2. Eject the iPhone from iTunes.
3. iPhone Settings > General > Usage > Storage > Music > Edit > Delete
4. Reboot your iPhone
5. Connect your iPhone to iTunes and attempt to manually sync the playlists in question.

Solution 2:

Assuming the duplicated songs were purchased from iTunes, you can go to Settings > iTunes & App Store, then turn off "Show All - Music". This toggle shows all the songs you have purchased regardless of if it is on your device or not.

Solution 3:

What I did:

1. Sync your iPhone with iTunes.
2. In iTunes, click Summary and uncheck Manually manage music and videos OR go to Music and uncheck Sync Music.
3. When prompted whether you wish to proceed -- because unchecking means the current music files in your phone will be erased, which is what you want to do to resolve this problem -- click Remove and Sync.
4. Next, eject the phone. Check phone to see if all music files are marked by the 'cloud download' icon, which indicates you successfully removed all iTunes files from your phone.
5. For further inspection, find the problem files that had shown up as duplicates on your phone. For me, the problematic tracks were no longer duplicated. If you still find duplicates on your phone, then go to iTunes, select 'Music', then select "Show Duplicate Items" from the View pull-down menu. Here you can delete any duplicate items. If you are using iTunes 12.01, click the 'Done' button when finished viewing file duplicates.
6. Restart your iPhone and connect to computer.
7. In iTunes, click Summary. Now with the problem resolved, you check Manually manage music and videos. OR in iTunes, click Music and check Sync Music.

Hopefully this works, if not, it's something to do with iCloud. Try disabling that and just backup on your computer. Then do it again.