Lost the plot?

[MDE]

Nor are quite a few other tags.

[musoware]

Could you list them so I can ensure they are covered?
(if possible, I'm at the mercy of what the taglib-sharp library can actually do)

[MDE]

Basically it seems to be the following which are missing:
(a) all tags which are not m4a native tags
(b) all import actions from custom tags (m4a native or not)
(c) certain m4a tags, where the original Muso mapping may no longer be correct
In particular, the following appear not to be working (category above is appended after each):
BAND (a) [ORCHESTRA doesn't seem to work either - I'm not sure which one Muso uses]
GROUPHEADING (b) [Work, which is the new m4a tag doesn't get imported either]
INSTRUMENT (b)
LABEL (a)
MAINPERFORMERINST (b)
ContentGroup (c) [Apple seem to have messed around with Grouping and ContentGroup - Muso may be mapping Grouping to Group Header, but I think the m4a tag now is ContentGroup]
Performer (a/c) [I'm not sure about this one - Edit ID-tag shows it as Title Case, which is generally indicative of a native tag - or at least what dBpoweramp thinks is a native tag, but it does not appear in iTunes "Get Info" or any other list of m4a tags]
PERIOD (b)

BTW, I find the attribute mapping (http://musoware.com/wiki/index.php?titl ... te_Mapping) very helpful, but it may be time to review this in the light of various changes in the past few years. Happy to help with that, if I can. Some other resources are https://picard.musicbrainz.org/docs/mappings/ (but it does not include the latest iTunes tags) and http://help.mp3tag.de/main_tags.html (which seems more up-to date). Neither of these seems to be fully accurate however- I will raise the mp3tag issues in that forum (like SHOWMOVEMENT does not seem to map onto the right iTunes tag).

BTW2 - I refer to m4a tags above as that is the filetype, but technically the tags are mp4, I think.

[musoware]

OK please try the latest patch and report back whether & how much this has advanced things.

[MDE]

That's fixed BAND, GROUPHEADING, INSTRUMENT, LABEL, MAINPERFORMERINST and PERIOD
But not Performer.
So looks like the custom tag imports are working at least, plus most of the others.

[musoware]

OK I will look at Performer next

[musoware]

I'm finding a PERFORMER tag is read correctly. What tag ID are you using for performer? I can't see it in your tag image.
I can get a MAINPERFORMERINST custom tag processed by the import actions OK with the current patch too.

[MDE]

I can't see it in your tag image.

That's because there isn't one for that album
It appears as in this one below

I also tried creating an import action, but that didn't work either.

[MDE]

(changed topic slightly for tracking purposes)
While I said that GROUPHEADING had been fixed, I should have been more precise. The m4a import problem has been fixed. However, I still have the problem, as originally reported, that the group headings are repeated in the titles as displayed.
This is a problem with the FLAC files as well as the m4a files. Previously, Muso recognised the text before a colon as being the group heading and stripped it out from the title if the group heading is specified (see extract from my website at bottom). Now it seems that is not the case. In fact the edit tracks seems to show a duplicated groupheading - so now it seems to be picking it up from both sources and duplicating it, hence it gets shown in the display.
How it looks in album view:

It used to look as shown on my website here: http://music.highmossergate.co.uk/screenshots.php
The Edit Tracks looks like this:

Note the duplication in the Group Header box.
(NB the tags are the FLAC tags as shown in an earlier post and the import actions are as previously specified)

Extract from my website:
Title {Base}
Sourced from:- Web-sourced metadata initially.
Before ripping, this should be set to be the work or opus (if any) followed by the movement, separated by a colon. This is a (fairly) standard naming convention for classical tracks. Check that only one colon is present. If more than one colon is present, the first one will be deemed to be the separation point between Work and Movement.

If the work is part of a larger opus (e.g. an Act within an Opera, or an opus within a collection such as the Well-Tempered Clavier) then the Title should be formatted as (e.g.) “Dido and Aeneas::Act 3, Scene 2: Dido’s Lament”. Muso will then use this to provide a three-level structure (“GroupHeader::GroupSubheader: Title”). You can also use this structure to provide a sub-heading for a work, e.g. “The Firebird Suite::1919 version: Introduction”. Provided you use the “Classical” Mp3tag action, any inconsistencies regarding spaces around the colons will be removed. If you want a track to appear in Muso as just a Work (with no movement) then use the format “Work: “.

Work and GroupHeading {Custom}, {Derived}
Sourced from:- Automatically by Mp3tag action from Title
Any words in Title and before the first single colon. (See Title tag for details). This populates the GroupHeader field in Muso (which then splits out any SubHeader). It can be amended in Muso and will update the Title field on export.

[MDE]

Posting this separately as we seem to have several separate issues here (topic amended slightly for tracking).
I don't know if it is relevant, but I am using dBpoweramp for file conversion. There are some peculiarities I have noticed: for example to get iTunes to import the Grouping (or is it ContentGroup?) tag, I have to call it Style in dBpoweramp. I don't know if similar issues affect Performer. I tried Soloists and that failed also, as did custom import action for Performer. For info, below is a complete list of the dBpoweramp native tags:
Album
Album Sort
Album Artist
Album Artist Sort
Artist
Artist Sort
Band
Chorus
Comment
Compilation
Composer
ComposerSort
Conductor
ConductorSort
Copyright
Disc
Encoded by
Encoding Tool
Genre
ISRC
Instrument
Label
Lyrics
Mood
Movement Count
Movement Name
Movement Number
Orchestra
Period
Rating
Show Work Movement
Soloists
SoloistsSort
Style
Tempo
Title
Title Sort
Track
UPC
Work
Year