Hello, I recently downgraded my macbook's hard drive size with the purchase of a newer macbook. I have my entire iTunes music library, around 150 GB. I'd like to be able to view my iTunes library in its entirety in iTunes, and be able to play from it when the external drive is plugged in. However, when I have the drive plugged in and change the iTunes media folder location to the folder in the external drive, nothing seems to happen. What gives?