I am sure many have noticed this but the train in the background at the meeting with Solozzo and McC... I believe you hear it once during the meeting and then again when Michael shoots them.... perfect timing... I love the build up visually and audibly
And Michael heard it too when he first sat down. I believe that is why he did NOT come out of the bathroom blasting away, like Clemenza originally instructed him to do. Instead, hearing that train rumble, he realized that it would be better for him to come out of that bathroom, sit back down, wait for another train to rumble on by and then shoot them both! He realized that the rumbling of the train would be somewhat of a distraction and would also help drown out the sounds of the gunshots.
