[X] Grouping tag - empty field doesn't show in iTunes?


I have recently realised that Apple stupidly changed the way they treat the "Grouping" information for tracks within iTunes (I'm on Windows 7 x64) - reading/writing this information now to a new tag called I believe "Grp1" whereas before it was something like "ContentGroup". So, I updated MP3Tag to v2.81 so I could see this tag.

I'm working with an .mp3 file. When I edit the "Grouping" tag in MP3Tag Editor, all the changes are correctly reflected in iTunes ("Grouping" field) except when I erase the tag contents (or set it to ) - then iTunes still shows the last non-empty tag content, not the empty content. If I close and re-open MP3Tag Editor with this .mp3 file, it still shows as a blank tag, but iTunes refuses to show this. Any changes I make the other way (ie edit in iTunes) work fine, including a blank tag.

I have tried this with MP3Tag set to read/write ID3v1 & ID3v2 tags, and also just with ID3v2 tags, with the same result.

Is this iTunes messing up or something in MP3Tag? I realise this "Grouping" tag was added in this latest version...

Thank you.


I do not think that it is possible to keep a field name but blank the data. I did not succeed to save an empty field definition.

So what is this about? That the iTunes database is not updated by iTunes?
I think the only way to do it is to delete the entry from iTunes and then add the file again.
In a way the described behaviour resembles the behaviour when compilation was set to 1 and removed later. The iTunes never released that track from the compilation display until it was deleted forcefully and reimported.
Is this so?


I didn't think to try deleting the tag itself, but I've tested that and I get the same thing - MP3Tag says the tag is gone but iTunes refuses to remove it.

I think this must be as you say - something wrong with iTunes; I did another test & added some Grouping tag information and also Composer, BPM, Disk Number tags to another .mp3 file. These changes show in iTunes OK. When I remove the tags again, they don't get removed in iTunes.

If I remove the track from iTunes, clear the Grouping tag and re-add it into iTunes, there is no Grouping data there. So, it looks like iTunes will read all .mp3 tags when the file is first added to the database, it will also read any changes made in a tag, but it will NOT read any empty tags and clear them in the database. I suppose this is by design, but it is annoying!

So, yes, I could remove all my affected tracks from iTunes and add them again but I really don't want to - I have playlists based on "Last Played" & "Play Count" information & I've spent years getting that info into the database! What a pain iTunes is !!!

OK, I think we are sure this isn't a bug with MP3Tag Editor - can a moderator move this thread somewhere else?


There is a way to do it, but I doubt it you will like it as it can be very tricky.

As you found out iTunes stores a lot of information in it's Database (iTunes Library.xml & iTunes Library.itl) files.

Please before doing anything of the following, BACKUP BACKUP BACKUP your iTunes.

The so called workaround consists of

  • Backup iTunes again :wink:
  • Shutdown iTunes
  • Remove iTunes Library.itl
  • edit iTunes Library.xml with a capable Editor and remove the offending tags
  • Start iTunes by Holding down the SHIFT key (select Choose Library) and browse to the iTunes Library.xml and check !
  • The iTL file will be rebuild with the info from the XML you just edited.

Good Luck !


Thanks, that is a useful tip... I have multiple backups of iTunes anyway but thanks for the warning too! I've delved into the Library XML file a lot, but I've never made changes to it before, I'd forgotten it could be used to rebuild the ITL file. A while ago I wrote a VBscript that would parse the XML file and get all the track, album ratings etc, then output it to a spreadsheet with meaningful data like my top 20 rated albums etc - it also warns me of any albums that have had their "Album Rating" forcefully set - a bug I've been fighting in iTunes or iphone for a while... I've noticed now that iTunes is syncing the same 160+ music tracks every time to my iphone, must be a corruption in the database so perhaps I'm due a rebuild!! I could kill, what, 4 birds with one stone?


Nope. NO corruption in the iTunes Database. Please read on.

I have been struggling with that BUG also !! You are lucky with your 160+, I think on my at one point it was around 2000. Even caused me to wipe my iPhone / iPod a couple of times because I thought it was corruption as you did.

I think I have to change my whole collection (over 12k), but I have been putting that off and because of this I stopped playing music via iTunes.

The Reason why it's doing this ???

Every time a song plays (MP3) which has CONTENTGROUP filled in, iTunes files WORK with the CONTENTGROUP tag. And for a UNKNOWN reason (to me that is) this causes you iDevices to SYNC these songs over and over and over again.

The solution:

Easy (when you know it) REMOVE WORK from the Song

Just add a column in iTunes which shows WORK and then remove.

Annoying problem this was, posted a topic about it on the iTunes discussion forum and it was 1st thought that it was Custom Lyrics, then Custom Pictures then .. then.. and then finally someone posted about the WORK.

I have made an action group in MP3tag (I use it on Mp3's only)
(Please note: this works only with MP3tag version 2.81 and up)

= 1st one =
Format Value:
Format String: $if2(%contentgroup%,%grouping%)

= 2nd one =
Remove Fields
Fields to remove: contentgroup


Hey Mike,
Do you think you could post a quick step by step into removing the conflicting fields from itunes, directed towards a beginner as I've never edited Itunes xml before.

My main problem with Mp3 tag is that it cannot read information edited on Itunes Grouping field, but can correctly read information entered inside of Mp3 tags system. This causes the problem where even if I edit the tag in mp3 tag, the id3 tag will say correct grouping but Itunes will have different entry, which is causing a lot of trouble.

I'm assuming using your fix through editing Itunes xml will work, but I'm worried where to start as I never have before.

If this helps, I've attached a screenshot of the Grouping column when I run your action.



If you have fears about the xml-editing way, why don't you update your iTunes library either with the "delete-(re-)import method" or with one of the update scripts?


Oh wow, for some reason I missed the notification about your post on 1st March! Your explanation makes sense, I have been using the "Grouping" field in iTunes for a while now to record textual information I can use to make Playlists, mostly to mark tracks I don't want synced to iphone (which explains why only a few hundred were constantly syncing...)

Unfortunately my PC system disk started dying so I decided to completely rebuild my itunes library from zero rather than bother with importing the old data (plus it had other issues...). I also decided to re-convert all my FLAC files (taken from CD) to ALAC and then to MP3 for some of the albums I'm less bothered about, so I'm having a huge tidy up - which is taking forever! Only when an album is converted like this have I added it to iTunes, I'm only on artists starting "L" ... lol.

But, with your advice above, I think I can re-import the rest of my existing MP3 collection by checking for the "ContentGroup" field and moving the data there to "Grouping". This should get around the syncing problem. Then I can convert the remaining files at my leisure!


PS I don't suppose you know what causes the "Album Rating" to mysteriously be filled in (as opposed to calculated) ?!