Carol Vernallis developed a theory of music video editing based on four key concepts: narrative and mise-en-scene, editing, camera movement, and diegesis. Her theory suggests that the video is a visual response to the narrative conveyed by the song's lyrics. She also notes that editing techniques can change the structure of music videos, and establishing shots and camera movements that follow the lyrics are conventions of music video filming. Diegesis, or the sounds within the world of the video, is an important part of constructing the music video experience.