Can't tag certain tracks

I just started using this today, and I’m confused why lot’s of files don’t get edited. They have a musical note icon next to them instead of the icon to indicate a match. Looking up in browser I can find the files.

The ones showing just a musical notes are just tracks that are part of the release, but there is no actual file attached to it. If you have a file for this track, but it is either still on the left pane or matched to a different release, then drag that file to this track and the icon will change.