I have some anniversary edition of "Animal House", and it has a great documentary on the production of the film, utterly fun and fascinating!
One of the most fascinating things was the choice of someone to write the original score for the movie, including the introductory Faber Theme which sounds like...formal college music.
John Landis wanted, out of the blue...Elmer Bernstein! Apparently, he wanted a "serious" score that would contrast the humor, not something frivolous sounding as was usually done. His family was apparently good friends with Bernstein, and his world class work up to that point included films like "The Great Escape", "The Ten Commandments", "True Grit", "The Magnificent Seven", "Quo Vadis", "The Man With The Golden Arm", etc.
He was puzzled when Landis called, but Landis was insistent over the objections of the film's backers and it was a huge success. After that, he did scores for "Ghostbusters", "Stripes", "Airplane!", "The Blues Brothers", as well as most of Landis's films for the next 15 years, including "An American Werewolf in London", and "Trading Places"!
After knowing this, when I watched the movie, paying attention to the soundtrack really changed everything! Almost like watching a new movie!
There were two other interesting things: They had everyone show up two weeks before the film began to allow people to "gel", which not only turned into two weeks of partying (and those who lived in the mid-Seventies knows what THAT was like...and there developed a real and actual clique stratification between the Delta House and Omega House...and the guy who played Niedermeyer wanted to hang out with them, but they wouldn't tell them when or where they were having parties!
Also...they visited an actual Frat house having a major party, and a huge brawl broke out where they were being beat up, kicked while on the ground and pummeled by hundreds of real hostile Frat guys who thought they were outsiders there hitting on their girls!