My band back in Highschool did that about 22 years ago. It was our homecoming parade. We were basically an oldies/classic rock cover band. Our generator died about 1/3 of the way through, so after while of standing there in silence, the drummer just broke into "Wipeout", and alternated between than, "Smells Like Teen Spirit" and "Enter Sandman" for the whole rest of the parade.
That's hilarious! Our PA overloaded two songs in but we had it fixed after about 15 seconds. Other than that it went off without a hitch!
Although on the dirty channel, my amp was picking up crazy noise from the generator for some reason.
I had to be quick on the footswitch for stops.