If it is in the key of C, the melody (played by the bass, keys and sung; it's not a masterpiece of arranging for a group) would be like this:
when c
love d
love e
will f
tear e
us d
a c
part a
a c
gain g
with the A and G being in the octave below the C, of course.
The verses are 12 bars each; keyboard part on the verse is simply
c (2,3,4) g(2,3,4) c(an octave up) (2,3,4) g(2,3,4)
then those 4 bars repeat:
c (2,3,4) g(2,3,4) c(an octave up) (2,3,4) g(2,3,4)
with the last 4 being a little different:
c(2,3,4) g (2,3,4) f(2,3,4) c(an octave up) (2,3,4)
hold down the C for the entire 12 bars for the verse, the other notes come in as outlined above.
when the G7 chord as used in the beginning comes back again near the end (it is used as the intro and bridge) being played by the guitar, the keyboard part is d and g (ascending). Then when the G7 chord stops for the last past where the song fades out, the keyboard goes to c and g (ascending), holding those notes down together.
I'm going by memory here but I'm pretty sure this is right. 'Round Midnight' it ain't. Of course if it is another key when JD did it all of it is wrong, but there's no reason you couldn't play it in C anyway for your cover.
No offense, but if you can't get that together, you may have not yet attained the level of mediocrity !
Nobody should have any trouble except maybe the drummer.
(edited because my ASCII description got messed with by the board)