Some Music is corrupt, program to check my files for consistency

I use a NAS as my iTunes storage.
The NAS isn't really very good and it seems some of the files are a bit corrupt, some of them play for half the song then stop for a bit then skip to the next file as though the rest of the song isn't playable.
some of the songs just have a slight skipping in the track like a CD is scratched.

Think is I don't know which are good files and which aren't.

At the moment when i hear a song hat skips i make a note of that song and re-rip it. but there is over 20,000 songs in my library so this method will take forever.

Is there a program that can scan my music files to see if they skip in places?

Thanks.