Stars like Paul McCartney, Mick Jagger, and Bruce Springsteen were interviewed about the Rolling Stone founder.
Wenner possessed a unique vision, Hagan said in a release.
He knew there was money to be made from day one.

As it turned out, there was millions.
The book will cover the success and romance surrounding Wenner, as well as the controversy.
That began a sometimes knotty conversation.
How would it work?
We finally agreed the book had to be independent.
I would report and write it, and he would provide all the access I needed.
But he would not have approval over the material.
Credibility was important to him.
And he wanted his story to be told in full.
It was also the only way I was willing to do it.
What has fascinated you most about him?His ebullient and infectious confidence.
And during this process, he could be breathtakingly honest.
Of course, I had the most fun coaxing rock and roll stories out of him.
The first one I remember was his description of Bob Dylans handshake totally limp.
Which interview were you most surprised or excited to secure?It was thrilling to interview Paul McCartney.
What surprised you most during the entire process?
I felt like a cross between Cameron Crowe and Philip Marlow part wide-eyed fan, part snooping detective.
And private letters from John Lennon.
How long have you been working on the project?In September, it will be four years.
Talk about a long, strange trip.