Within the properties for any Track, there are several fields that are specific to Album attributes. Specifically, Album and Album Artist. These fields are edited in the same way as any other, but affect how Albums are displayed in the main panel in a manner that might not be obvious at first.
For a set of Tracks that are part of an Album by a single Artist, the Track Artist and the Album Artist will be identical for every Track on the Album. Thus any operation that changes the Track Artist (e.g. Drag and Drap from Artist 1 to Artist 2) will automatically change the Album Artist.
Multiple Artist Albums are slightly more complex as they have a common Album Artist (often called 'Various' or 'Various Artists'), but multiple Track Artists. For instance, "The Big Chill" has an Album Artist of 'Various Artists' but the Track Artist for "I Heard it through the Grapevine" is 'Marvin Gaye'. This will be represented in the Tree:
In the Albums node as:
The Big Chill (Various)
In the Artists node as:
Marvin Gaye - Track: I heard it through the Grapevine
Various - Album: The Big Chill
Thus you can easily find the Tracks by any individual Artist, as well as the Albums by the Album Artist. If you Drag and Drop a Track from an Album in which the Track and Album Artists do not match, from one Artist to Another, only the Track Artist will change. Similarly, if you drag the Album from one Artist to another, only the Album Artist will change.
If you have several Tracks that are all part of the same Album, but the Track Artists are all different, and for each Track, the Track Artist = Album Artist, then your Tracks will not be represented properly in the Tree, since the Album Artist is incorrect for every Track.
You can correct this type of situation through the following steps:
The properties and tags will update, and the Tracks and Albums will now display properly.