Analysing Opening Sequences - Introduction

To start with I'm going to be looking at five opening sequences from films from different genres, to get an idea of the conventions that come up in opening scenes, regardless of genre. I think that the purpose of opening scenes in films is pretty consistent, whatever the genre, though there might be some differences between, for example, a thriller and a comedy. 

From watching films, I think that most opening scenes introduce the important characters and use mise-en-scene and music to let the audience know what genre the film belongs to, but I'm going to see if there are any more purposes for opening scenes, and record my findings here. 

I also expect to see titles and production company logos.

The films that I am looking at are:

'Get Out' (Horror)

'Ghostbusters' (Comedy)

'Passengers' (Science Fiction)

'Eden Lake' (Horror)

'Mission Impossible' (Action Film)

'Django Unchained' (Western)