work name, name and movement

It would be interesting to see if iTunes updates any fields in the files at all.
AFAIK the only way is to transform the tags which forces iTunes to write the information to the files.
Perhaps you then see the information.

I have saved the work, movement tags in both mp3 and m4a inside iTunes.

iTunes doesn't write any new id3tag. iTunes is saving the tags in iTunes library.

Anybody has more information we will be greatly appreciated.

As I said: you can force iTunes to write the database contents to files by using the function to convert the tag version (V1, V2.3, V2.4 etc). This should work even if you transform V2.3 to V2.3.

I've tried to write the tags into the files by transforming them in iTunes. The WORK tag is written to CONTENTGROUP, but the MOVEMENT tag is not written at all, neither are the sentence numbers.

The TITLE by the way is not altered at all.

Does anybody know a way of forcing iTunes to accept a tag written by Mp3tag as MOVEMENT and it's associated number?

Sorry, tag should be called MOVEMENT, of course...

for M4A:
Workname is written to -> ©wrk
Movement "name" is written to -> ©mvn
Movement number is written to -> ©mvi and ©mvc fields
Grouping is written to -> contentgroup
unknown field -> shwm is set to 1

check the m4a file using mediainfo.

I've added the new fields with the current Development Build Mp3tag v2.79b.

The following fields are available for ID3v2 and MP4 tags

The WORK field is only available for MP4 tags. For ID3v2, what is filled in the Work Title in iTunes is currently displayed as CONTENTGROUP in Mp3tag. The developers at Apple decided to reuse this field which was previously used to store what is filled in Grouping. This information seems now to be stored in the iTunes database only and not in the ID3v2 tag. For MP4, what is filled in Grouping is still presented under CONTENTGROUP in Mp3tag.

It's unfortunate that they've created this inconsistency here. If someone from Apple is reading this, I'll happily discuss a more robust approach.

I have extracted information from an m4a file using newest iTunes (version in mac. Work and contentgroup are written to two separate fields.

However, mp3 is still messed up. I have reported this issue in If you have better idea to implement, please let me know. I can update it in the discussion I am having with them.

Format : MPEG-4
Format profile : Apple audio with iTunes info
Codec ID : M4A (M4A /mp42/isom)
File size : 9.41 MiB
Duration : 5mn 1s
Overall bit rate mode : Variable
Overall bit rate : 261 Kbps
Album : album
Album/Sorted by : album
Album/Performer : albumartist
Album/Performer/Sort : albumartist
Grouping : grouping2
Performer : Artist
Performer/Sorted by : Artist
Composer : composer
Encoded date : UTC 1959-07-26 04:13:07
Tagged date : UTC 2016-11-15 06:21:16
©wrk : WORK1
©mvn : MOVEMENT1
©mvi : 1
©mvc : 2
shwm : 1
Composer/Sort : composer

also please implement the field "shwm"->SHOWMOVEMENT. if it is set to 1, it will show movement in the iTunes otherwise it will show song name.

SHOWMOVEMENT would indeed be a great addition, because it would also help me using the new tags in my favourite player foobar2000. In fact this gives me the opportunity to tag my classical music in a proper way at long last. :smiley:

Just out of curiosity: How did you find out which ID3v2-tags iTunes accepts as its own unofficial ones for its database?

me too I am curious. mediainfo is only these fields update for m4a not for mp3.

Please update SHOWMOVEMENT for both m4a and mp3.

Please update the WORK to mp3 also. iTunes has confirmed this is coming in iTunes and later.

I'm quite fluent in reading ID3v2 from hex :slight_smile:

It seems like there is no ID3v2 frame which indicates this flag. It seems for ID3v2 (i.e., MP3 files) they determine to show the movement based on – again – data that is only stored in iTunes' internal database.

This I cannot do (yet) as I cannot know how they'll implement this.

Kind regards
– Florian

Just to understand this correctly:
Is iTunes defining its own ID3v2 frames? For me it looks like the frames used are
MVIN for the movement number and
MVNM for the movement name.
I always thought this would have to be a TXXX frame...

Could you post a link, please?

Wonderful. Mediainfo is showing the changes for only for m4a and not for mp3.
If you can please give more info about it. It will be a good learning. Or if there is any other application that serves the purpose, please let me know.

"shwm" is the id3tag written for m4a.

I am sure same field is used in mp3 also. I updated two mp3s, one with movement and one with song info in mac and copied the files to windows. iTunes in windows showed the song info on one file and movement on another file.
This is clearly shows, "shwm" field is also written in mp3.

Please verify the mediainfo output in my previous post, it clearly shows, "shwm" is written to m4a.
One check. In iTunes, you have to write some info to movement and work, and most importantly leave the song at movement toggle and close the song. then review the file.

If you write in the movement and work fields and set the song back to song. iTunes will not write "shwm" field. It either writes "shwm"=1 for movement or nothing for song display.

If you need I can upload 2 m4a's and 2 mp3's, one each in different condition.

As soon as it is out, I verify the work and grouping fields are independent. I will report it here.

Thank you for updating the mp3tag with new fields and also keeping it free. It deserves donation for sure.


It is in bugtracker. If you need proof, we can wait for the iTunes update.
Below is the response to my query.

The “grouping” string is now written to an ID3 frame as of iTunes

Thanks, don't need proof for that!
I was just curious about it... :slight_smile:

FYI, ID3v2 tags are written to MP3 files, MP4 files have a complete different tagging scheme which is based on atoms that have identifiers (i.e., shwm as you mentioned).

This I couldn't verify with MP3. If you have an example MP3 files with such tag field, I'm happy to analyze it.

Kind regards
– Florian



I am sorry, I was wrong. "shwm" is found in only m4a, as of now. Issue of this field(or something comparable) not found in mp3 is reported as bug. I feel that they will fix it. Since they asked for additional information. Fingers crossed!

If you can please be kind enough (as usual), add support "shwm" for m4a. As soon as, I hear something about mp3, I will update in this forum. "shwm" is set 1 if movement info needs to be displayed. if song info needs to be displayed, iTunes doesn't write this field at all.

iTunes update is not released, yet. grouping vs work for mp3 should be fixed then. As soon as, I see a new update on iTunes. I will test and report here.

Thank you for continued support.

Apple says they are supporting below fields for mp3 in new version of iTunes

  • movement name: 'MVNM'
  • movement number: 'MVIN’
  • work name: 'TIT1'
  • grouping: ‘GRP1'

I have verified this in hex editor. But for some reason, the same is not seen in mediainfo. Nonetheless, fields are implemented in iTunes.

Please verify the same and update mp3tag.

Also, has the grouping field changed from previous iTunes version?

Looks like iTunes has switched the field for grouping.
Earlier it was mapped to 'TIT1', now to 'GRP1'.