Making the audience scream.

We like to have "surprise" moments in the Royal Edinburgh Military Tattoo. In this particular one we emulate a violent multi-bike collision by the totally unsubtle use of large quantities of simultaneously fired maroons on the bikes. It's very loud and makes the audience scream and jump with such simultaneous force that the whole lighting gantry makes a strong "whump" sensation. Awesome!
My camera auto-muted the violence of the actual explosion despite me putting a bit of tape over the microphone to try and cut the sound levels down.