J & L Cuts are used by editors to create a seamless flow during conversations, lead audiences along in a story by providing information, or give a dialogue a deeper meaning.
A J cut is when the sound of the upcoming scene starts before its visuals. It can also be referred to as an audio advance or audio lead. It is called a J cut because of the shape it makes in the editing program with the sound coming before the picture.
An L cut is when the visuals of the upcoming scene start before its sound. It is called an L cut because of the shape it makes in the editing program with the visuals coming before the sound.
The movie “Fight Club,” starring Brad Pitt and Edward Norton, is about a white-collar office worker who can’t sleep at night and forms a “fight club.” A clip of the movie located at https://www.youtube.com/watch?v=CR5Jp_ag2M8 shows an L cut at :25 when Norton begins to talk. The visuals still show Pitt. This allows the audience to see Pitt’s reactions to Norton as they discuss Norton hitting him. We get to see Pitt psyching himself out to get ready for the punch by jumping up and down and laughing.
The 60 second doc titled “Karaoke Bus” located at https://www.youtube.com/watch?v=v_dwTN0x2L8 is about a mobile karaoke lounge. There is a J cut from :00- :08 where the documentary begins with Kestrin Pantera talking while b-roll footage is shown of the mobile karaoke lounge. We finally see her talking at :09. I think the J cut was made because the visuals are so powerful; it is more effective to show the people having fun doing karaoke than showing Pantera just talking about them having fun doing karaoke. It is a great way to conceptualize what is being said.