I recently read the entry for 18 May 1966 in Mark Lewisohn's The Complete Beatles Recording Sessions, which details the session at which the saxophone and trumpet parts for "Get to Get You into My Life" were recorded. Yester-day, I figured out one of the saxophone parts (although, of course, I think I figured out the one that's least interesting to listen to on its own), so now I can put it together with the bass part, which I learned in March. After I'd recorded both of those, I also figured out an-other phrase (which I think is trumpet), which makes this a little more interesting to listen to. I don't know how to play saxophone or trumpet, so I used mellotron voices on my keyboard.
In the original recording, it sounds - to me, anyway - as if McCartney plays the first bass note simultaneously on two different strings: a G on the fifth fret of the D string and the open G string. I'm not sure if that's really what's going on there, but that's what I did in my recording. The longer the fade-out goes on, the less confident I am in my accuracy. I think I flubbed a note there too.