Depends on The Genre The conventions of a music video vary depending on genre of music. However, some general conventions apply to the majority of music video’s.
Artist’s performing The majority of videos consist of the artist performing in the video. As one of the purposes of a music video is to raise awareness of the artist, then it is common sense for that artist to appear in the video.
Visualizing the Lyrics the lyrics of the song influence what is shown in the video. For example The song Last Friday Night (T.G.I.F)by Katy Perry is a good example of this as it about a teenage girl reflecting on her experiences from the previous Friday night which strongly influences the mood of the video which consists of a party scene. Link for Song www.youtube.com/watch?v=KlyXNRrsk4A
Pace of Editing The pace of editing fits the pace of the music The song Jar of Hearts by Christina Perri is a good example of this. The song has a very slow tempo and this dictates the video which has a slow level of editing. This makes the duration of the shots longer, making the video appear slower to match the pace of the song. Link For Song http://www.youtube.com/watch?v=8v_4 O44sfjM
Mise En Scene The Mise en scene of the video is very important and it should comply with the mood of the song. If a song was very cheerful, then you wouldnt have costumes which are associated with sad or depressing experiences, such as funeral directors etc.