Sound

Diegetic Sound - on or off-screen sound that belongs to the scene, naturally (e.g. car radio music, a stereo playing in a lounge scene, bird song, traffic, wind etc).

Non diegetic sound - sound is music or other audio that is not natural to the scene and is added (or 'normal' sound is enhanced by the use of effects) to add meaning /impact to a scene.

Synchronous sound - sound that appears to be matching a certain movements  occurring in the scene, for example when footsteps correspond to feet walking.

Asynchronous sound -   Sound which is indigenous to the action but not precisely synchronized with the action.

Leitmotif - A musical phrase (tune) that is repeated several times in a piece of music and helps to represents a particular character, idea or situation. For example the iconic 'Pink Panther' theme tune

Contrapuntal Sound - Sound that doesn't seem to fit with the scene