I believe the singers were placed in the middle of the orchestra during the recording to evoke "the human part in the machine" (I think it's mentionned in the liner notes). Removing them may be tricky, then?
where the piece between - please see my video in this thread
There's lighthearted music between those two cues in the movie, but it is tracked in from second half of "25. Plans To Eliminate Mayor." As stated, re-used cues are not all included. Your clip doesnt start with lighthearted music, so I dont know what scene you're doing.
I dont have the slate numbers for the cues. The cue list I posted is in film order. You can always email me if you want more details.
My only source is the full score - which is why i was able to create the MIDI file - i don't have the film here in front of me, allthough it is here somewhere in my house