20 Things You Somehow Missed In Friday The 13th (1980)
19. Music To Kill By
Harry Manfredini's soundtrack score serves an incredible purpose in helping to set the scene, not only in the original Friday the 13th, but also in the sequels for which he returned as composer.
Compared to other famous slasher movie soundtrack scores, Manfredini mainly only scored sequences in which the killer is present to avoid being accused of trying to manipulate the audience through too many jump scares.
Manfredini struck horror-score gold with his iconic theme for the film (which later became the key theme for the franchise) when he adapted Betsy's Palmer's line "Killer her mommy" into the iconic "ki ki ki ma ma ma". The composer spoke the syllables "ki" and "ma" into a microphone that had a delay effect, essentially repeating the sounds.