iTunes Displays Albums Incorrectly
In some views, iTunes may show albums sorted incorrectly, or show all or some of the artist's albums under a single album heading.
This may occur if multiple albums have the same Sort Album value. This may happen if a selection of tracks belonging to an album with a Sort Album value (for example, if it begins with “A” or “The”) are modified to appear listed under a different album title. In this case the songs appear under the new album title, but in some views the Sort Album value takes precedence.
To resolve, clear the Sort Album field for all tracks. iTunes will recreate a value in that field if necessary.
Another cause of albums/artists not appearing in the expected place is if the tracks have the Part of a compilation flag set. Change this to No.