Cannot change movement number or name of a classical piece in iTunes
Discovered that I can edit those fields in my library, but not in the import window.  And I can't get access to the file from the import window to change tags.  That is, “show in finder” is not on the context menu in that window.

Thus, I can make them correct in my library, but I can't send the corrections to Gracenote.

While fiddling with this I also discovered that if I select a track in the import window and change tags, the changes do not “stick” if the import of that track has already completed.  For example, select all of them and fix a typo in the album name: I end up with two albums, one with the wrong name and the first few tracks, and my correction on the other tracks.