I just picked up Jimmy Smith : Root Down [Live]...OMG:eek:

NNNAAAAAASSSSSSSTTTTTYYYYYYY

Wilton Felder plays bass and man oh man, this thing is just blistering.

On the 1st song 'Sagg Shootin' hs Arrow' the progression is a fast bluesy kinda thing, nice pumpin bass line. And then at around 2:12 into the song suddenly Wilton does the thing were it just changes in a big way. Suddenly it sounds like he is playing a jazz tune and he is just walking it over a series of chords. It sounds like a very common jazz type of line and I would like to understand it.

I am not looking someone to say "he's playing yadda yadda yadda" moreso, I want to understand whats happening. (I plan on learning specifically what he doing when I have some time to sit down and work it out --- then I will study it for myself)
Is he playing appeggios over multiple chords within the context of the key? Is he simply walking over notes in the primary scale? Is there some standard approach or a pattern that is found to be common among jazz bass players that is somewhat of a framework which sounds solid enough on it's own merits and yet can be expounded upon?

Anything? Anyone? Just looking to improve my playing here and will appreciate anything that anyone has to offer (even if you don't know this songs specifically - if you understand the jist of what I am asking and can help, please do).

...it sounds like he is playing a jazz tune and he is just walking it over a series of chords. It sounds like a very common jazz type of line and I would like to understand it.

Is there some standard approach or a pattern that is found to be common among jazz bass players that is somewhat of a framework which sounds solid enough on it's own merits and yet can be expounded upon?

I haven't hear this tune...sounds like you're describing 'walking bass over changes'.
There is a standard approach that can be solid...and, yes, it can definitely be expanded upon.
Too, the 'best' improvise on the fly...so, I wouldn't say they're using 'patterns', per se, although there are certain figures that do get repeated.

Listen to the masters-Blanton, Mingus, Ray Brown, Paul Chambers, Sam Jones, Ron Carter, etc. Transcribe...

There are some pretty decent books out there, too-
I recall seeing a Paul Chambers & Sam Jones bass book being reviewed in Bass Player about a year or so ago.
Jamer Aebersold has a few Bass Books with plenty of walking bass-style tunes.
Ed Friedland has two nice books that deal with the style.

Part I is deciding upon what notes to play; Part II deals with 'feel'.

Good luck & happy listening.