"Compilation tag" not recognised by mp3tag?

I recently ran across a somewhat curious problem which I believe is worth pointing out here.

I imported several CD's either as original disc or as flac or mp3 from the net in to iTunes/iPod touch and used the onboard converter to translate mp3 into m4a. This all worked fine and all releases by that particular artist ended up in iTunes under the correct band name.

However, upon synchronizing the iPod, one of the albums was missing under the band name although it was present as an "album". There was no clue within the informations how this could occur. After quite some fiddling around - including rebuilding the data base - I checked with mp3tag for the details of these particular mp3's which had served as source - nothing.

It then turned out that apparently this particular album was tagged as "compilation" and hence treated differently by the iPod touch as compared to iTunes. Well, no commentary required, I assume.

But I could not get rid of this hidden tag neither by iTunes nor by mp3tag.

I finally resorted to reconverting the files via audacity into wav and concurrently removed all "suspicious" data upon conversion, then reloaded the files into iTunes and reconverted the wav files into m4a.

That did the trick.

Apparently, there are tags in mp3 which can even be carried over into wav and do not show up in mp3tag.

No, I think this only an iTunes problem with its database.
iTunes never updates that field once it has read it.
So even if you remove the field with MP3tag (which works) then iTunes still keeps it in the database.
You would have to delete the entries from the iTunes database and then reread the folders to add the entries again.

Well, thanks for that hint as to the iTunes database. I did, however, remove the item and reintroduced it - to no avail. AND - I did not see that "Compilation" flag in mp3tag. There, everything looked fine. Only thing I could think of would be that reloading the (edited) mp3 did not cause iTunes to change its database entry and hence kept the original problem.

If so, this would mean that you do have to resort to "intermediate" wav or aiff with troubled mp3's, since that conversion/re-import did the trick.

I am not quite sure of what you mean by

as when I talk about "remove" then this means I select the entry in iTunes and call the function Edit>Delete. iTunes then asks whether the track should be moved to the bin which I deny.

I think iTunes allows to add an extra entry in the column browser at "Artist" for compilations.
Selecting this pseudo-artist then shows all files that are tagged with the compilation field.
You can drag&drop these from iTunes into MP3tag and inspect them there.
While you are at it you could check that you only have V2.3 tag versions and not such things as APE tags in the files.
Remove the field COMPILATION in the extended tags dialogue (for those files where you do not want it) and then use the Delete function in iTunes for these files.
(Preferably you delete all files with the field COMPILATION unless they are part of valuable playlists).
Then rebuild the iTunes library.
Right now iTunes should not know anything about COMPILATIONS anymore at least for these files.

Now this was an essential hint. I could have saved a lot of time if I only would have looked more closely into mp3tag. :frowning:
I was not aware of the "alt-T" option and hence did not locate the "compilation" tag in the extended info dialogue when I used mp3tag (I also never would have thought of just dropping a track from iTunes directly into mp3tag!). Sure enough, there WAS an entry - which I removed via the rather mad approach by audacity. Good hint! Thanks a lot. mp3tag is even better than I thought. It should be ported for Macs, btw. :wink:

it has been ported for Macs. See here: