The whole song just repeats a 4 measure chord progression of Bbmaj7, Cmaj7, and Ebm.
 
 Bmaj7 C#maj7 Em
|--6-----8-----7--|
|--7-----9-----8--|
|--8-----10----9--|
|--9-----11----9--|
|-----------------|
|-----------------|

               Bmaj7
Uh, was always smart-mouthed and quick-witted
                         (Bmaj7)
But somethin' was always missin' like six digits
                     C#maj7
Lucky seven probably poppa
                     Em
Little nigga so they picked on him, hassled him
Bbmaj7
Things changed when I hassled back, so
      (repeat)Bmaj7
David hit the...


The trumpet is only playing the arpeggio of each chord.
and that's it.