Beastie Boys as Old school, Xzibit if it is 2018.

I would go for something old school like the already mentioned beastie boys. Sabotage is not really a typical song for gansta rap but sounds pretty cool. If it should sounds like 90th I'd go for something from Dr. Dre or Snoop dog. As the story plays in the near future I'd expect somebody to listen to Xzibit.

Various classic quality

DJ Kool - Let me Clear my Throat

http://www.youtube.com/v/54yIMKjG048?fs=1&hl=en_US

You might want to check out Jester (anyone should, really); it's a Norwegian underground-rap artist, and he does a lot of great stuff. Their new album is even called "Aiming at the Moon, Landing on the Roof".. First, check out "Survive" (old single) from the link I give (notice the lyrics):

http://www.nrk.no/urort/Artist/Jester/default.aspx

If you can work out anything for them in the movie, I think you could magnify the "underground" feel of both parts :D<

Now THIS could be awesome to have somewhere in the movie!

http://www.youtube.com/v/1fd9qP-sHbQ?fs=1&amp;hl=en_US

Adding this because it's quality old Scandinavian rap (which sorely need to get a "comeback") I guess this fits better for the credits rolling text but you know best. In worst case I shared quality music with this community ^^

http://www.youtube.com/v/8E-fgk8HEKc?fs=1&amp;hl=en_US

http://www.youtube.com/v/6P9IHMyMeYc?fs=1&amp;hl=en_US

Run D.M.C. - "Raising Hell"

Pretty much anything off "Raising Hell". So much better than the later "gangsta crap". Basically invented the modern rap genre. Basically invented rap-rock fusion 20 years ahead of it's time.

"It's Tricky" is a personal favorite.

http://en.wikipedia.org/wiki/Run%E2%80%93D.M.C.

http://en.wikipedia.org/wiki/Raising_Hell_(album)

Beastie Boys - Sabotage

Since rap honestly seems like an odd choice for this movie, this is more rock than rap, and it kicks ass.

Some quite old songs

Nas - If I ruled the world feat. Lauryn Hill

I think this could work...

Has to be Public Enemy

Just a question of which track.

Burn Hollywood Burn
Public Enemy #1
Uzi
Revolverlution

... would all be solid choices. But seeing a Moon Nazi dancing to Fight The Power could perhaps be the ultimate movie moment EVER.

Ice Cube - Gangsta Rap Made Me Do It (Official Video)

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Mobb Deep - Shook Ones Pt.II

-95 old school enough?

Onyx - Shiftee