I regret that songs like "green mouse" are not complete. Only the first two sentences every time. The principle is still nice and attractive to baby. It is easy to learn, not too heavy and baby can easily press one of the buttons. The sound although a little loud even on the lowest level, is good. The book is easy to clean, a little bit of sponge and go again!
Plus: a Velcro fastener to hang
For the price, I recommend this book anyway, especially for a 9 month old baby. This is suitable. (Note the price I saw him yesterday, twice in supermarkets.)