The solo is a series of 1/16th notes played with triplet
You may have heard that the last half of the solo is the front
part played backwards. That's mostly true —— the first
three notes of the second measure are not repeated.
(The "X" at the end of the first measure may or may not be
included, but it's hard to tell).
Given this, there is no "right" way to play this as it sounds
on the recording. I have included the second measure with
its dynamics. Surprisingly, it is playable, and probably
really good practice for your slap bass "chops".
First measure (played as recorded):
P S S S s S S S S
1 + 2 + 3 + 4 +
Second measure :
S S S S S S S S S S S P S
1 + 2 + 3 + 4 + 1
If you go back and listen to the original recording, the bass
player plays this so fast and clearly it's amazing.
By the way, I spent hours looking at this with SlowGold; I
would bet my life on the accuracy of the non—"x" notes in
this transcription (not the fingering, though... who knows
that the original bass player really did).