thanks for the helpful replies. I put in a request on the wish list.
I'm seeing some funny things happen in the tag inspector...
1) inside MusicBee preferences, I set my custom tag to "save to music file as tag" key.
2) I tag an mp3 file using MixedInKey
3) I import the file to MusicBee and inspect the tags:
Name Tag Code Value
INITIAL KEY TKEY 2A
4) the "key" field inside the Tags (2) remains blank.
5) I manually edit the "key" field inside Tags (2). I enter "9A" and save the changes.
6) I view the tag inspector again:
Name Tag Code Value
INITIAL KEY TKEY 2A
KEY TXXX/TKEY 9A
7) now I open the mp3 in foobar / serato. both programs read the key as 2A.
8 ) I clear the "key" field inside Tags (2). It is now blank again.
9) inside MusicBee preferences, I set my custom tag to "save to music file as tag" initial key.
10) re-scan library.
11) the "key" field inside the Tags (2) now displays 2A.
so, when a custom tag is set to "save to music file as tag" key, it fails to read/write the actual id3 tag "INITIAL KEY". however, when a custom tag is set to "save to music file as tag" initial key, it reads/writes the actual id3 tag "INITIAL KEY" just fine. I'm wondering what the difference is between the tag codes "TXXX/TKEY" and "TKEY"... and overall I am just very puzzled :/
do you think if I change the custom tag display name to "Initial key", or the custom tag identifier to "Initial key", this might fix the problem?