To tell you that the CD is full of children singing. And I don't mean in a nice, trained choir sort of way, I mean as in a classroom full of untrained child voices doing shouty singing (roughly in tune, but completely unbeautiful).
I just bought a new CD for DS in the car, full of great songs and rhymes. But I honestly can't listen to it, it's so grating. You can't hear the words properly either. I wouldn't choose to listen to adults who do not know how to sing properly, so why would anybody think it's ok for children? (the exception obviously being your own children, who sound beautiful whatever noise they actually produce). Of course children should be encouraged to sing, but dont record it and then SELL it to me, especially without any sort of a warning. DS doesn't seem too keen either.
So why make these sorts of CDs at all? It just isn't a nice sound. Or maybe it's just me......