So today, I was reorganizing my music. I went and opened my music app and several songs disapeared. Restarting did NOT help.Here is the complete solution :-Go to Settings>Applications >All-Find the app Media Storage (its icon is an android with a white cube)-Tap it, When ready, tap "Clear Data"-Download this app https://play.google.com/store/apps/d....media.scanner -After it installs, open it and click "Start Scan", I recommend staying inside the app and waiting.-Toasts will appear as it progresses-After it finishes, go back to your music/video app.-.-.-.-.-.-.-.-.-Galaxy Tab 2 7.0 P3100