Is this one of those CDs where the main artist asks their friend to sing a song with them?
Such as, Slash's new album. Track 1 is "Slash Feat. Ian Astbury", track 2 is "Slash Feat. Ozzy Osbourne" and so on.
To fix this, select all the tracks on that album, right-click > Get Info, and say YES to changing multiple items.
Put "Slash" in the *Album Artist* field (for this example, of course).
Make sure it is the *Album Artist* field, not the plain Artist field.
On the holds out, you can select all the album tracks, right-click > get info.
Re-type the Album name. Sometimes one of the tracks may have a blank space at the end. You can't see it but itunes does and decides it's a separate album.
You can also try the trick of checking and unchecking the "Part of a Compilation" box as described here