Some songs are skipped over/broken on my iPhone; how can I find these? Sometimes when I go to play a song on my iPhone, it skips over it entirely and goes onto a song after it in the list.

The same happens when I try and play it in iTunes directly from the device - it gets a exclamation-mark-circle icon to its left when I try and play.

The songs have all been copied on by drag/drop from MP3 folders, so I suspect the copy process didn't completely properly.  Is there a way I can find all these songs so I can re-copy them?  (Trying to copy the entire album over again creates duplicate entries.)
Finally found an answer to this, thanks to Galley from iLounge!


Create a standard playlist called "Not Missing".
Drag your entire library into that playlist. Missing tracks cannot be copied to a playlist.
Create a smart playlist called "Missing" where:


Playlist - is not - Not Missing
(additional to this post)  Media type - is - Music



You now have a playlist which contains only your songs with the dreaded exclamation mark, and you can re-add them from your original source.