Lets take a look at a few things.
Tony Robbins and other self help people. Although a bit scammy in some aspects it is almost impossible to put down a disc and not feel enthralled to do something positive. even if we are alone we can surround ourselves with podcast and such to provide ourselves with positive mindsets which are transferable.
Magic mushrooms Psilocybin to be more exact is another example of how others moods and ideas can affect us is such a positive or negative way. Anyone with experience will be able to relate and hopefully more as they continue research using this compound regarding depression and marital therapy.
On the opposite spectrum we have gangster rap music. I believe undoubtedly that if the majority of the music would be about more positive and responsible aspects of "hood life" or whatever you want to call it it would help the majority of people involved.
I studied people, men to be exact during my three year stint in a state penitentiary and it truly is amazing how us humans are influenced by what we are around and who we are with. Just some things on my mind I would be happy to answer any questions.