I posted a couple of months ago about Jimmy Page's editing on Led Zeppelin videos, how according to one dedicated fan, Eddie Edwards, Page took the best parts of several shows and edited them into a perfect idealized Led Zeppelin concert. Gjertsen's video is that concept taken to the extreme. (Yes, I thought it was already at its extreme too. Apparently not.)
I found this mentioned on Mick Farren's blog. The video shows what happens if you can't play drums or piano, but you are technically fabulous enough to take a video of you playing every beat and note and then edit the single clips into a coherent musical piece. It's funny, clever and very musical. I'm now a fan.