I have to admit that it took me fifty years to understand that some band players are just 'hired guns', never knew about that, I always thought they just played in different bands as full members. So for that only this documentary was an eye opener for me, and a good reason to watch it. It was very interesting to see the view of those artists on the bands they played with, and how some of those 'celebrities' are just a bunch of egoistic egocentric bastards, like Billy Joel in this documentary. He's a heartless very self-centered egoistic prick that doesn't deserve anybody buying his music. On the other hand you can witness what a wonderful guy his drummer Liberty DeVitto is, still forgiving everything and playing for peanuts. But there are also others than Billy Joel that are just wannabe good people and I guess that once you got a bit of success you just look at other people like they are your possession. In this documentary you also discover nice celebrities, with a golden heart, like Alice Cooper, Ozzy and Pink, not directly people that I would have thought being nice persons in daily life. So never judge a book by it's cover. The documentary is very well made, with tons of relevant interviews of great side artists, guitar and drum virtuoses that made the name of some big bands without ever being recognized. Interviews with hired guns, producers, artists and so on, it all passes the revue and it's very interesting and pleasant to listen to. If you are a music fan you should definitely watch Hired Gun. I will always listen to music in a different way now.