I was trying to think of the best examples of this....

I think 'Ain't no mountain high enough' is a great one. Lots of the Marvin stuff like 'what's going on'. I searched around and another GREAT example is his playing on the Jackson 5's 'Darling Dear'. In fact that might be the absolute best example of it...there's even an allusion to what you're talking about in the description here:

http://www.youtube.com/watch?v=ND-iW51idC0&feature=related

Also noticed there's alot of Jamerson basslines on youtube isolated as solo tracks. Lots of stuff to check out.