Who came up with the idea for iPhone, iPod, iPad, and iTunes? Not Steve Jobs?

I am reading the book "Start wit why?" And in it the author states that Steve Jobs did not come up with the idea for iPhone, iPod, iPad, and iTunes; but instead Steve foster an environment where people were free to come up with crazy ideas.

Is this true?

Does anyone have any good resources like books/articles on the matter?

Thanks in advance.