I don't listen to much rap but i came across this song and apparently figured it out.
All of the low notes are F5 and it is played at random times
E|-|
B|-|
G|-|
D|3|
A|3|
E|1|
and after he says "don't quote me boy cause I ain't said shit"
E|------------------------------|
B|------------------------------|
G|------------------------------|
D|5-5-8----5-5-3---5-5-8---5x5-3|
A|------------------------------|
E|------------------------------|
If I ever listen to this song again I will try to find those high notes.