Movies Under The Stars ( MUTS ) apparently isn't such a new idea.
A few weeks ago I picked up an old Hope/ Crosby / Lamour
" Road to Rio " movie . I think these were made in the late 30's-early 40's.
Hope and Crosby had stowed away on an ocean liner bound for Rio.
One scene showed the passengers sitting around on the main deck one night watching a movie. So it appears at least the idea has been around sometime.