Horner composed many scores for many films, not least Titanic and Aliens, and is well know for his work of Star Trek II: The Wrath Of Kahn. His name was one of professionalism, just witness the Aliens making of, where Horner speaks about writing the score to a movie that was still being shot.
Horner scored and wrote many of the films of my generations childhood. Field Of Dreams, Jumanji, Commando, Willow. And yet more. His work lives on, and "Bishop's Countdown" from the afore-mentioned Aliens has appeared in so many trailers and teasers.