Over time the princibals of editing has changed and developed with technology there is now programs such as final cut pro,at first editing was as simple as cutting a piece of film and joining it back again. Now there's all sorts of ways to illustrate a song such as mixing graphics in with original footage using editing software. There is now ability to have better transitions between shots as well. When music videos was in its early stages the shot types were simple and mainly mid/long shots because this was before people realized using close-ups can tell a story or have vital information in a subtle way,for example like 1:22 into the music video kickstart (http://www.youtube.com/watch?v=OCmO-C9D3zE) it shows a tattoo on someones neck later showing that tattoo is connected to a gang and allows you to work out who's on who's side. also now using different angles such as low-angle looking up at someone gives them power and this can be used simple way but effectively to give you a incite and feel of the character on screen. There is a unwritten rule that you don't go past 180o for the reason that the viewer finds it easier to follow a story that is set out in a clear way,in many shows there is a wall that you don't get to see this is also for the reason of having a big film crew set up across the line and it helps to frame shots. Creating pace in a video is done by cutting quicker transitions between shots, this speeds up the atmosphere and when accompanied by a dramatic sound bed engages the viewer massively. A motivated shot is when you know whats comeing,for example if someone was to look shockingly towards a door the audience would have a good idea what the next shot is,it will most likely show the door or whats behind it. Jump cuting is a quick transition between any seleted shots. Clearly thorght out transitions can be used for different effects for example a slow fade to black can indercait the ending of the song or fadeing to black and white can indercait the past. Cross fades can show the passing of time these are all the small things that are esential to make a video work and be sucessful. A montarge is generaly used with photograths but can be used in film,a monaerge is when there is various quickly selected shots. This can be used efectivly in a flshback of someones life. Point ov view shot is where your seeing what the charater is seeing threw thire eyes and is used alot to show panic or disstress in films. An example of a Cut away is when someone is talking or in this scenario singing and it will cut/fade to a shot of a beach while they sing about it.