Sound design and Soundtrack music.

Nearly every movie, tv show, commercial, etc. uses sound design and or soundtrack music.  Oddly enough most of the sound is not recorded with the picture.  Spoken dialogue by the main actors is recorded at the same time but by a different method and sometimes replaced later. Nearly all of the background sounds are taken out and added back in later. This is where sound design, sound effects and foley come in adding the footsteps, ocean, door banging, dog barking, every sound you need to hear. Soundtrack music is often written directly for the movie matching the scenes in the movie by playing MIDI piano while watching the movie, capturing the excitement or emotion  of the story.