You can call up a list of all the songs with a specific word in their title, album name, or artist attribution, just by clicking the Source pane's Music icon (under Library) and typing a few letters into the Search box in iTunes' upper-right corner. With each letter you type, iTunes shortens the list of songs that are visible, displaying only tracks that match what you've typed.
For example, typing train brings up a list of everything in your music collection that has the word "train" somewhere in the song's information—maybe the song's title ("Mystery Train"), the band name (Wire Train), or the Steve Earle album (Train A Comin'). Click the other Library icons like Movies or Audiobooks to search those collections for titles that match your search terms.
Another way to search for specific titles is to use the iTunes Browser mentioned earlier in this chapter. If the Browser pane isn't showing on screen, press Ctrl+B (⌘-B) to summon it. The Browser reveals your collection grouped by Artist, Album, and Genre. Hit those keys again to close the Browser.