How to get iTunes to recognize "missing" albums?

[bigwig]

In my "iTunes Music" directory I have albums that iTunes doesn't have in its album or track listing. Somehow their info has gone missing. I tried dragging the directory to the iTunes window, but its scan didn't pick up the "missing" albums. How can I regenerate the correct album listing within iTunes?

 

[Trainwreck707]

What happens when you drag the folder of a missing album back into the itunes window? If you double click on a missing song from inside of its folder does it play? Finally, have you checked the compilations section in itunes?