Display WD shared music by iTunes genre?

We backed up all my iTunes music on the WD My Book World Edition from my iMac. Now when we bring them up in iTunes (from the WD) all we get is the listing of albums and song titles, but we don’t get either the genre info or the coverflow cover art. Should we have copied over something else from my iMac? This is making it difficult to find specific albums and artists easily.  We’re accessing the music on other home computers.