The hum of four Pratt & Whitney R-1690 engines isn’t something you hear everyday. Sounds like victory.
I used to live out by Indianapolis Regional Airport (nee’ Mount Comfort Airport) where they stage these shows. One day I was outside and heard the drone of the engines and looked for the plane. it took at least 5 minutes before it came into view. I remembering thinking what did a 1000 plane raid sound like? The Germans had to hear them coming when the crossed the Channel.