This problem goes back some time, but see if you can help... I had a MacPro '06 but it was giving me loads of problems. After weeks of trying to fix it, Apple gave me a new MP '08. In the process, the store itself did the data transfer - this was back in Feb / March. So every once in a while, when I'm listening to iTunes, it's unable to locate a song. I haven't had a problem tracking down the song which is usually in my iTunes library. I think the problem stemmed from the fact that when I switched from a PC to a Mac I had all this music that I copied from the drive in my old PC to the "Macintosh HD" and then added the music to my iTunes library. What I later realized what that iTunes was making a copy of my music so instead of 80GB of music I now had 160GB. At that point I learned that iTunes could reference music and movies without copying them into it's library. So, I had this mix of music in my iTunes library and music that was being referenced on another drive. In any case, I have this weird situation now where all the titles of the songs show up in my iTunes library but I have no idea how many iTunes won't be able to find. Lately, as I've been using the Genius feature, some of the songs have cropped up with a little exclamation point next to them. As I've said, I can track them down, so I don't think I've actually lost anything but I don't know why iTunes isn't finding them. Is there anyway, to go through iTunes and actually figure out which songs are going to have an exclamation mark next to them without playing all 15,000 or 20,000 songs and then rebuild the database?