Ivan: Now that we know the microfilm is safe, when do we dispose of boy?Ambassador: It will be at the very end of Natasha's solo. You will take a gigantic leap into the air. Just as your feet touch the ground, there will be a cymbal crash, and when that cymbal crashes, we will shoot him.Ivan: How did you ever think of such an intricate plan?Ambassador: I saw it in a movie.
The movie the ambassador refers to seems to be The Man Who Knew Too Much; a key element of the movie's plot is an assassination attempt on a prime minister during a performance at the Royal Albert Hall where the gunshot is meant to be disguised by a cymbal crash.