No Orchestra or Ensemble tags?

Hey, I just started using mp3tag on macos. I'm in the process of ripping a lot of classical CDs and there seems to be no way in the macos version to add tags for Orchestra, Ensemble, Performer or Soloist, even though those are common tags used by online databases. So for example if an online database has an orchestra or soloist tag, that is added to the file and mp3tag can edit it. However, if that tag is not included in an online database, then I cannot add that field in mp3tag on macos.

Is this really the case or am I missing something?

Are you sure that these real tag fields and not simply labels?
ID3V2.3 tags allow user-defined tag fields - perhaps you find your data there.
In MP3tag you see the field names in the extended tags dialogue - press ⌘ T.
If you want to re-use that name, type it in whereever you are asked for a field name.

Seems like a real tag to me and it is retrieved correctly from online databases. However, if another file does not have that tag, then I cannot add it in the macos version of mp3tag.

You have to type in the fieldname.
MP3tag will remember it then.
Please note that ORCHESTRA is a user-defined tag field which is probably not displayed by most players.

If online databases are using the tag, I'm not worried about whether a specific player displays it or not.

Please also note that you can add each of those fields to the Tag Panel and the File List as outlined at Customization of Tag Panel and File List .

Thank you, Florian. Yes, I was expecting to be able to go into extended tags, add a field and put in a custom name there. Except when you do that, the ok button is greyed out.

In case anyone comes across this in the future here are the two ways Florian suggested.

First, you can add a custom field to the tag panel on the left side of the UI by going into Settings/Tag Panel. The one disadvantage of this is that if you then want to hide those custom tags in the panel, you have to go back into the settings to deactivate them.

The other way is to go into Settings/File List and add the tag with the following formatting for the Value and Field information. Then it will show up in as a column the main UI to the right and can be hidden by right clicking the column and unchecking it.

I would suggest adding the capability to the extended tags window at some point just because expected behavior would be that one could add a custom tag there by typing it in, especially when that window does show custom tags if they are in the metadata and can edit them as well.

Adding any custom tag field via Extended Tags is already possible -- you'd need to enter a value in the edit dialog for the OK button to be enabled.

Please note that there can not be "empty" tag fields in a tag. Either there is data labelled with a certain field id or there nothing. You cannot create empty tag fields for future use.