By hearing and evaluating the bass note(s) and Pat's melodic (and harmonic) material, I was able to construct a reasonably accurate/correct Harmonic analysis. (The Real Book is Real Wrong in this example.)
For instance - in m3 & 4 - Jaco plays MOSTLY Bb's (NOT A's) there... He also sometimes plays some (high) harmonic D's and A's on top of the Bb low note - thus - Bb maj7 + Pat's E in the melody = Bbmaj7, #11.
Having some keyboard skills ( and also some of the Dreaded Music Theory ) will help you "hear" and be able to analyze and make sense of Harmonic structures.
Also - SING as much of the melody as you are able to. Sing along with the recording many DOZENS of times to internalize the melody. Later, you can find the melody on your bass.
Good Luck!
Thanks for your interest and civility.
Ok cool that makes sense. Thanks.
No Eb in the melody then I guess. (Which is for me to go and figure out)