What would happen to the TV and Music industry if Music labels and movie companies would be required to give there content back to creators.?

If you mean what if studios didn't have ownership of anything they help make. Well the money to make things has to come from somewhere. So that means the stars of things would make a lot more money, and would have to fund their own projects. I think that could lead to some more interesting and unique visions, but also could lead to more stinkers if the person has bad instinct or taste. Also, depending on the type of person they are they're more likely to waste all their own money on addictions then never be in anything again because they can't fund their projects. So yeah while it could have some good outcomes in certain situations with a smarter creator its not going to be 100% positive. People will mess up just like tv studios do, and then its possible we'll never hear from them again after depending on the circumstances. 

I don't  understand. How can you give "content" back, it's an idea? A plot?

   If you mean Royalties; I'm all for it. The movie "Tombstone'" didn't give a Nickel to the real city  of Tombstone,  did not film one  frame there. In Old Tucson and a build-up  set in the vicinity. The mayor of Tombstone is a bit sore on this point.