I'm not sure if this set any kind of record for the biggest sing-a-long, but it has to be close.

If you've ever been to a concert in your life, you know there's a little downtime before the show starts and in between the opening band and the headliner as the stage crew tears down one set and gets the next one put up. Unless it's a festival then there's downtime between each band, but you probably figured that out.

If you've not ever been to a concert or festival, let me quickly explain what happens. Concert organizers will typically pipe in music through the PA system to keep the crowd from rioting while they are crammed like sardines waiting on the band they paid $40 (or more) to see take the stage. This music generally falls within the same genre of the bands performing.

For example, at a Green Day show in London a week or so back, while the stage hands did their thing, the sound operator blasted Queen's "Bohemian Rhapsody" through the arena's sound system, much to the delight of the 60,000 people in attendance. They enjoyed it so much, they collectively decided to sing along. And it went a little something like this.