Do you have disappearing music on your iPhone? Is your music gone? If you've recently updated to iOS 4.2 you may have had the frightening experience of all your media content disappearing for no reason. Don't worry, the fix is quite easy. There appears to be a bug in iOS 4.2 but here's the fix.
Plug your iPhone into iTunes
When your iPhone shows up in the sidebar, look for the content listings under your iPhone it (click on the triangle to the left if to view it)
Select Music
Play one of the songs in iTunes
Sync your iPhone
Your music should reappear
Sometimes just doing a sync of your iPhone provides the fix. Hope this helps!
Sometimes just doing a sync of your iPhone provides the fix. Hope this helps!