example of CD DISC ROT - laser audio media

I was cleaning up a box set called "Star Time" 
from 1991 by James Brown. 

It was made in canada and consists of 4 cd's in standard jewel cases 
housed in a long box with booklet. 

 On disc 3 which was incidentally what appears to be the 
most played disc there was some odd black 'growths'
in the silver media layer. It looks like natural type phenomena
but what happened is whatever grew eliminated ALL the
 silver layer where the 'dark' area is. 

When I held it up to the light was when I realized it just gaps
 through the CD itself. The largest growth is through the 
last part of the disc (the outside edge) and growth almost as
 big at the first track (inside) which makes the track 1 (mother popcorn) 
a write off after 30 seconds in. Odd thing is the area spreads into
 track 2 (funky drummer) which plays fine .

 There is a few ticks here and there on the 2nd last track and otherwise , for some silver layer eliminated, I'm very surprised the other tracks play as well as they do.

 Enjoy the pics.