The Foos were performing in Edmonton, Canada when Dave Grohl mentioned he couldn't remember all the lyrics to Rush's "Tom Sawyer". A fan was pulled out of the crowd and survived the pressure of doing live karaoke with one of the biggest bands in the world in front of tens of thousands of people.

Here's another angle of the video:

 

Okay, even if Brian wasn't necessarily "good" (it's hard as hell to hit Geddy Lee's high notes) you gotta give the guy a ton of credit for having the balls to get up there! If Dave Grohl ever told me something I did was "f*cking amazing", I could die a happy man right then and there.