Sound used to represent teenagers

The Tv Drama that i have decided to deconstruct in order to find out how representation is found for teenagers is Misfits.
Non-Diagetic:
 While recapping the previous episode the sound used is fast pace to highlight immediately the fast paced lifestyle that the teenagers characters live. However what contrast to the representations of children is that the sound used is rather old fashionned and not at all current but more of a car song.
Despite this the non diagetic sound becomes more diagetic once it has finished recapping the previous episode.
Then it straight away cuts into the opening credits so  it is clearly apparent that loud music plays an important role in teenagers lives.
After it the non diagetic sound becomes pleanastic because the sound used is heighted and exxagerated to highlight maybe the seriousness of the next scene.
After the plot of the episode is established it cuts into diagetic sound swiftly, this is shown by "Nathan" The main Character calling his father, who we the audience actually hears the phone call.