I was wondering if I can index music from an external HDD in iTunes so that it syncs to my iPod when the HDD is connected. This is just for music that I don't listen to on a regular basis, and then have my regular music on my laptop's HDD. I know it's possible to just not copy to iTunes library, but they still show up in my library but won't play. I want to know if I can make them disappear until I connect the external, and have them appear again. Thanks!