Hi!
I just purchased MJ8 yesterday and installed the MJ9 Beta. Very cool, especially like the ability to manage image files as well.
Had a minor tagging disaster yesterday. I selected the Music node in Media Library. I was experimenting and typed in a new Album name in the right-hand tag editor, and it changed the Album field of all of my 1000+ MP3s!
I know it's not a bug and I blundered, but I think it would be more intuitive and safer if you had to have one or more or all files selected in the contents view to which such changes are applied. Ie, not to assume an implicit select-all as it appears to do. I think if you type in a new tag value when no tracks are selected, it should present you with a dialog box asking if you want to apply the change to all tracks in the contents view:
No tracks are currently selected! Instead apply tag change to all files shown in Contents Pane?
[Yes] [No]
No should be the default each time. To avoid the message you should first click in the Contents Pane, do a Select All (Ctrl+A) then type a new value in the tagging pane.
Fortunately I think I can fix the tags with a retag-from-filename operation.