My Macintosh HD shows 49.74 GB of audio. I'm a music file glutton that's been using iTunes/iPods/iPhones as my main music player for about 12 years, and sure enough, my iTunes Library is roughly 50GB. But since I got a MacBook Air, I moved my whole iTunes Library and all individual files to an external USB drive. I can only listen to iTunes or sync an iDevice when this USB drive is plugged in. After I transferred all my music to the external hard drive, and a back-up hard drive too, I deleted it from the MacBook Air. Sure enough, the Music folder under my username has very little in it. There are no other users or user accounts on this machine. What's going on here? Thanks in advance!