Totally stumbled upon this collaboration. We were getting some ice cream (24 hour soft serve, woo!) and were going to sit down behind the stage when Fred mentioned that Isaac, Taylor and Zac would be joining him. This video is from the side of the stage because it was as close as we could get at that time. But a TON of the non fans were totally impressed that Hanson did this with Cowboy Mouth.
[youtube=http://www.youtube.com/watch?v=FNSzGV4zE08&hl=en&fs=1]