Understanding Music For Film & Television

Diegetic Sound:
Diegetic sound means that you can see where the sound is coming from in the scene/movie. For example:

*A car engine starting up.
*2 characters having a conversation.

Non-Diegetic Sound:
Non-diegetic sound means that you can't see where the sound is coming from within the cinematography. For example: 

*Music that plays at the start (introduction) of a movie.
*Commentary (i.e. a character telling a story, someone narrating something, etc).

Foley Sound:
Foley sound is done by a foley artist and their job is to recreate sounds that would come from the movie scene they're given to increase the quality of the audio to make the scene more genuine & convincing. For example, a foley artist would use certain items for certain sounds:

*Punch meat on a hook to imitate the sound of punches.
*Tap their feet on the spot to imitate walking, if they were to imitate running then they would tap their feet faster and a bit harder.

In this scene from "The Matrix", you have clear examples of diegetic, non-diegetic & foley sound: Diegetic - Morpheus speaking to Neo (0:13)
Non-diegetic - Neo opening his eyes (0:00 - 0:05)
*Foley - Neo swinging his arms (0:44)

The foley artists may have recreated the sound of the fight by punching meat on a hook to recreate the sound of the punches, tapping their feet on the floor to resemble the character's bare feet moving on the floor and swiftly waving paper by the microphone to replicate arm movements.

The use of these types of sounds improved the fight scene because not only did it make it more intense, it also responded to what was going on in the scene. One clear example is at the very start of the scene as the music started off very intense then when Neo opened his eyes, a crash (from a drum kit) cancelled out the intense sound at the start, making way for diegetic sounds (characters speaking & beeping of the monitor) then when the scene changes, another non-diegetic sound (asian drums) becomes the driving force of the scene because it plays a big part of keeping the attention of the audience. Examples of the drums responding to the scene can be found at 0:11 - 1:13.

Temp Tracks:

Temp tracks are tracks that are based off of another track that will try to recreate the same feeling that was created in the original track (in this case, the director would give it to the composer).

 (Above is the actual introduction of the movie while below is the temp track)

 

Wild Tracks:

Wild tracks are simply recordings of an environment and you can hear the sound that the environment is generating.

 

It's very likely that it's been recorded in a place where the overall volume isn't high which means you'll notice the wild track much more in the recording.

Composite Tracks:

Composite tracks is all the sounds relevant to the scene (speaking, music, ambience, etc) would all be put together in one audio file.